Secondary Menu

Navigation

Archive | Encyclopaedia

Maslow’s Hierarchy of Needs

By on 9th May 2013 in Psychology 0
TwitterFacebookLinkedInGoogle+bufferEmail

Page semi-protected
An interpretation of Maslow's hierarchy of needs, represented as a pyramid with the more basic needs at the bottom[1]

Maslow's hierarchy of needs is a theory in psychology proposed by Abraham Maslow in his 1943 paper "A Theory of Human Motivation".[2] Maslow subsequently extended the idea to include his observations of humans' innate curiosity. His theories parallel many other theories of human developmental psychology, some of which focus on describing the stages of growth in humans. Maslow used the terms Physiological, Safety, Belongingness and Love, Esteem, Self-Actualization and Self-Transcendence needs to describe the pattern that human motivations generally move through.

Maslow studied what he called exemplary people such as Albert Einstein, Jane Addams, Eleanor Roosevelt, and Frederick Douglass rather than mentally ill or neurotic people, writing that "the study of crippled, stunted, immature, and unhealthy specimens can yield only a cripple psychology and a cripple philosophy."[3] Maslow studied the healthiest 1% of the college student population.[4]

Maslow's theory was fully expressed in his 1954 book Motivation and Personality.[5] While the hierarchy remains a very popular framework in sociology research and secondary and higher psychology instruction, it has largely been supplanted by attachment theory in graduate and clinical psychology and psychiatry.[6][7]

Hierarchy

Maslow's hierarchy of needs is often portrayed in the shape of a pyramid with the largest, most fundamental levels of needs at the bottom and the need for self-actualization at the top.[1][8] While the pyramid has become the de facto way to represent the hierarchy, Maslow himself never used a pyramid to describe these levels in any of his writings on the subject.

The most fundamental and basic four layers of the pyramid contain what Maslow called "deficiency needs" or "d-needs": esteem, friendship and love, security, and physical needs. If these "deficiency needs" are not met – with the exception of the most fundamental (physiological) need – there may not be a physical indication, but the individual will feel anxious and tense. Maslow's theory suggests that the most basic level of needs must be met before the individual will strongly desire (or focus motivation upon) the secondary or higher level needs. Maslow also coined the term Metamotivation to describe the motivation of people who go beyond the scope of the basic needs and strive for constant betterment.[9]

The human mind and brain are complex and have parallel processes running at the same time, thus many different motivations from various levels of Maslow's hierarchy can occur at the same time. Maslow spoke clearly about these levels and their satisfaction in terms such as "relative," "general," and "primarily." Instead of stating that the individual focuses on a certain need at any given time, Maslow stated that a certain need "dominates" the human organism.[10] Thus Maslow acknowledged the likelihood that the different levels of motivation could occur at any time in the human mind, but he focused on identifying the basic types of motivation and the order in which they should be met.

Physiological needs

Physiological needs are the physical requirements for human survival. If these requirements are not met, the human body cannot function properly, and will ultimately fail. Physiological needs are thought to be the most important; they should be met first.

Air, water, and food are metabolic requirements for survival in all animals, including humans. Clothing and shelter provide necessary protection from the elements. While maintaining an adequate birth rate shapes the intensity of the human sexual instinct, sexual competition may also shape said instinct.[2]

Unbalanced scales.svg
 The neutrality of this article is disputed. Relevant discussion may be found on the talk page. Please do not remove this message until the dispute is resolved. (February 2013)

Safety needs

With their physical needs relatively satisfied, the individual's safety needs take precedence and dominate behavior. In the absence of physical safety – due to war, natural disaster, family violence, childhood abuse, etc. – people may (re-)experience post-traumatic stress disorder or transgenerational trauma. In the absence of economic safety – due to economic crisis and lack of work opportunities – these safety needs manifest themselves in ways such as a preference for job security, grievance procedures for protecting the individual from unilateral authority, savings accounts, insurance policies, reasonable disability accommodations, etc. This level is more likely to be found in children because they generally have a greater need to feel safe.

Safety and Security needs include:

  • Personal security
  • Financial security
  • Health and well-being
  • Safety net against accidents/illness and their adverse impacts

Love and belonging

After physiological and safety needs are fulfilled, the third level of human needs is interpersonal and involves feelings of belongingness. This need is especially strong in childhood and can override the need for safety as witnessed in children who cling to abusive parents. Deficiencies within this level of Maslow's hierarchy – due to hospitalism, neglect, shunning, ostracism, etc. – can impact the individual's ability to form and maintain emotionally significant relationships in general, such as:

  • Friendship
  • Intimacy
  • Family

According to Maslow, humans need to feel a sense of belonging and acceptance among their social groups, regardless if these groups are large or small. For example, some large social groups may include clubs, co-workers, religious groups, professional organizations, sports teams, and gangs. Some examples of small social connections include family members, intimate partners, mentors, colleagues, and confidants. Humans need to love and be loved – both sexually and non-sexually – by others.[2] Many people become susceptible to loneliness, social anxiety, and clinical depression in the absence of this love or belonging element. This need for belonging may overcome the physiological and security needs, depending on the strength of the peer pressure.

Esteem

All humans have a need to feel respected; this includes the need to have self-esteem and self-respect. Esteem presents the typical human desire to be accepted and valued by others. People often engage in a profession or hobby to gain recognition. These activities give the person a sense of contribution or value. Low self-esteem or an inferiority complex may result from imbalances during this level in the hierarchy. People with low self-esteem often need respect from others; they may feel the need to seek fame or glory. However, fame or glory will not help the person to build their self-esteem until they accept who they are internally. Psychological imbalances such as depression can hinder the person from obtaining a higher level of self-esteem or self-respect.

Most people have a need for stable self-respect and self-esteem. Maslow noted two versions of esteem needs: a "lower" version and a "higher" version. The "lower" version of esteem is the need for respect from others. This may include a need for status, recognition, fame, prestige, and attention. The "higher" version manifests itself as the need for self-respect. For example, the person may have a need for strength, competence, mastery, self-confidence, independence, and freedom. This "higher" version takes precedence over the "lower" version because it relies on an inner competence established through experience. Deprivation of these needs may lead to an inferiority complex, weakness, and helplessness.

Maslow states that while he originally thought the needs of humans had strict guidelines, the "hierarchies are interrelated rather than sharply separated".[5] This means that esteem and the subsequent levels are not strictly separated; instead, the levels are closely related.

Self-actualization

Main article: Self-actualization

"What a man can be, he must be."[11] This quotation forms the basis of the perceived need for self-actualization. This level of need refers to what a person's full potential is and the realization of that potential. Maslow describes this level as the desire to accomplish everything that one can, to become the most that one can be.[12] Individuals may perceive or focus on this need very specifically. For example, one individual may have the strong desire to become an ideal parent. In another, the desire may be expressed athletically. For others, it may be expressed in paintings, pictures, or inventions.[13] As previously mentioned, Maslow believed that to understand this level of need, the person must not only achieve the previous needs, but master them.

Research

Recent research appears to validate the existence of universal human needs, although the hierarchy proposed by Maslow is called into question.[14][15] Other research indicates that Maslow's explanations of the hierarchy of human motivation reflect a binary pattern of growth as seen in math. The individual's awareness of first, second, and third person perspectives, and of each one's input needs and output needs, moves through a general pattern that is basically the same as Maslow's.[16]

Following World War II, the unmet needs of homeless and orphaned children presented difficulties that were often addressed with the help of attachment theory, which was initially based on Maslow and others' developmental psychology work by John Bowlby.[17] Originally dealing primarily with maternal deprivation and concordant losses of essential and primal needs, attachment theory has since been extended to provide explanations of nearly all the human needs in Maslow's hierarchy, from sustenance and mating to group membership and justice.[7] While Maslow's hierarchy remains a very popular framework in sociology research and secondary and postsecondary psychology instruction, it has largely been supplanted by attachment theory in graduate and clinical psychology and psychiatry.[6]

Criticism

In their extensive review of research based on Maslow's theory, Wahba and Bridwell found little evidence for the ranking of needs that Maslow described or for the existence of a definite hierarchy at all.[18]

The order in which the hierarchy is arranged (with self-actualization described as the highest need) has been criticized as being ethnocentric by Geert Hofstede.[19] Maslow's hierarchy of needs fails to illustrate and expand upon the difference between the social and intellectual needs of those raised in individualistic societies and those raised in collectivist societies. The needs and drives of those in individualistic societies tend to be more self-centered than those in collectivist societies, focusing on improvement of the self, with self-actualization being the apex of self-improvement. In collectivist societies, the needs of acceptance and community will outweigh the needs for freedom and individuality.[20] The term "Self-actualization" may not universally convey Maslow's observations; this motivation refers to focusing on becoming the best person that one can possibly strive for in the service of both the self and others.[10] Maslow's term of self-actualization might not properly portray the full extent of this level; quite often, when a person is at the level of self-actualization, much of what they accomplish in general may benefit others or, "the greater self".

The position and value of sex on the pyramid has also been a source of criticism regarding Maslow's hierarchy. Maslow's hierarchy places sex in the physiological needs category along with food and breathing; it lists sex solely from an individualistic perspective. For example, sex is placed with other physiological needs which must be satisfied before a person considers "higher" levels of motivation. Some critics feel this placement of sex neglects the emotional, familial, and evolutionary implications of sex within the community, although others point out that this is true of all of the basic needs.[21][22]

Changes to the hierarchy by circumstance

The higher-order (self-esteem and self-actualization) and lower-order (physiological, safety, and love) needs classification of Maslow's hierarchy of needs is not universal and may vary across cultures due to individual differences and availability of resources in the region or geopolitical entity/country.

In one study, exploratory factor analysis (EFA) of a thirteen item scale showed there were two particularly important levels of needs in the US during the peacetime of 1993 to 1994: survival (physiological and safety) and psychological (love, self-esteem, and self-actualization). In 1991, a retrospective peacetime measure was established and collected during the Persian Gulf War and US citizens were asked to recall the importance of needs from the previous year. Once again, only two levels of needs were identified; therefore, people have the ability and competence to recall and estimate the importance of needs. For citizens in the Middle East (Egypt and Saudi Arabia), three levels of needs regarding importance and satisfaction surfaced during the 1990 retrospective peacetime. These three levels were completely different from those of the US citizens.

Changes regarding the importance and satisfaction of needs from the retrospective peacetime to the wartime due to stress varied significantly across cultures (the US vs. the Middle East). For the US citizens, there was only one level of needs since all needs were considered equally important. With regards to satisfaction of needs during the war, in the US there were three levels: physiological needs, safety needs, and psychological needs (social, self-esteem, and self-actualization). During the war, the satisfaction of physiological needs and safety needs were separated into two independent needs while during peacetime, they were combined as one. For the people of the Middle East, the satisfaction of needs changed from three levels to two during wartime.[23][24][25]

A 1981 study looked at how Maslow's hierarchy might vary across age groups.[26] A survey asked participants of varying ages to rate a set number of statements from most important to least important. The researchers found that children had higher physical need scores than the other groups, the love need emerged from childhood to young adulthood, the esteem need was highest among the adolescent group, young adults had the highest self-actualization level, and while old age had the highest level of security, it was needed across all levels comparably. The authors argued that this suggested Maslow's hierarchy may be limited as a theory for developmental sequence since the sequence of the love need and the self-esteem need should be reversed according to age.

See also

References

  1. ^ a b Maslow's Hierarchy of Needs
  2. ^ a b c Maslow, A.H. (1943). A theory of human motivation. Psychological Review, 50(4), 370–96. Retrieved from http://psychclassics.yorku.ca/Maslow/motivation.htm
  3. ^ Maslow, A (1954). Motivation and personality. New York, NY: Harper. p. 236. ISBN 0-06-041987-3. 
  4. ^ Mittelman, W. (1991). Maslow's study of self-actualization: A reinterpretation. Journal of Humanistic Psychology, 31(1), 114–135. doi: 10.1177/0022167891311010
  5. ^ a b Maslow, A. (1954). Motivation and personality. New York, NY: Harper.
  6. ^ a b van IJzendoorn MH, Sagi-Schwartz A (2008). "Cross-Cultural Patterns of Attachment; Universal and Contextual Dimensions". In Cassidy J, Shaver PR. Handbook of Attachment: Theory, Research and Clinical Applications. New York and London: Guilford Press. pp. 880–905. ISBN 9781593858742. 
  7. ^ a b Bugental DB (2000). "Acquisition of the Algorithms of Social Life: A Domain-Based Approach". Psychological Bulletin 126 (2): 178–219. doi:10.1037/0033-2909.126.2.187. PMID 10748640. 
  8. ^ Steere, B. F. (1988). Becoming an effective classroom manager: A resource for teachers.. Albany, NY: SUNY Press. ISBN 0-88706-620-8, 9780887066207 Check |isbn= value (help). 
  9. ^ Goble, F. (1970). The third force: The psychology of Abraham Maslow. Richmond, CA: Maurice Bassett Publishing. pp. 62.
  10. ^ a b Maslow, A. (1954). Motivation and personality. New York, NY: Harper
  11. ^ Maslow, A. (1954). Motivation and personality. New York, NY: Harper. pp. 91.
  12. ^ Maslow, A. (1954). Motivation and personality. New York, NY: Harper. pp. 92.
  13. ^ Maslow, A. (1954). Motivation and personality. New York, NY: Harper. pp. 93.
  14. ^ Villarica, H. (2011, Aug 17). Maslow 2.0: A new and improved recipe for happiness. The Atlantic. Retrieved from http://www.theatlantic.com/life/archive/2011/08/maslow-20-a-new-and-improved-recipe-for-happiness/243486/#.TkvKIRv8USE.facebook
  15. ^ Tay, L., & Diener, E. (2011). Needs and subjective well-being around the world. Journal of Personality and Social Psychology, 101(2), 354–365. doi: 10.1037/a0023779
  16. ^ Cronburg, T. (2010). Maslow 2.0 human hierarchy of needs [Image]. Retrieved from [1]
  17. ^ Bretherton, I. (1992). "The Origins of Attachment Theory: John Bowlby and Mary Ainsworth". Developmental Psychology 28 (5): 759–775. doi:10.1037/0012-1649.28.5.759. 
  18. ^ Wahba, M. A., & Bridwell, L. G. (1976). Maslow reconsidered: A review of research on the need hierarchy theory. Organizational Behavior and Human Performance, 15(2), 212–240. doi: 10.1016/0030-5073(76)90038-6
  19. ^ Hofstede, G. (1984). The cultural relativity of the quality of life concept. Academy of Management Review, 9(3), 389–398. Retrieved from http://www.nyegaards.com/yansafiles/Geert%20Hofstede%20cultural%20attitudes.pdf
  20. ^ Cianci, R., & Gambrel, P. A. (2003). Maslow's hierarchy of needs: Does it apply in a collectivist culture. Journal of Applied Management and Entrepreneurship, 8(2), 143–161.
  21. ^ Kenrick, D. (2010, May 19). Rebuilding Maslow's pyramid on an evolutionary foundation. Psychology Today. Retrieved from http://www.psychologytoday.com/blog/sex-murder-and-the-meaning-life/201005/rebuilding-maslow-s-pyramid-evolutionary-foundation
  22. ^ Kenrick, D. T., Griskevicius, V., Neuberg, S. L., & Schaller, M. (2010). Renovating the pyramid of needs: Contemporary extensions built upon ancient foundations. Perspectives on Psychological Science, 5, 292. doi: 10.1177/1745691610369469
  23. ^ Tang, T. L., & West, W. B. (1997). The importance of human needs during peacetime, retrospective peacetime, and the Persian Gulf War. International Journal of Stress Management, 4(1), 47–62.
  24. ^ Tang, T. L., & Ibrahim, A. H. (1998). Importance of human needs during retrospective peacetime and the Persian Gulf War: Mid-eastern employees. International Journal of Stress Management, 5(1), 25–37. Retrieved from http://www.springerlink.com/content/h1q9vg84760uhh5u/
  25. ^ Tang, T. L., Ibrahim, A. H., & West, W. B. (2002). Effects of war-related stress on the satisfaction of human needs: The United States and the Middle East. International Journal of Management Theory and Practices, 3(1), 35–53.
  26. ^ Goebel, B. L., & Brown, D. R. (1981). Age differences in motivation related to Maslow's need hierarchy. Developmental Psychology, 17, 809–815. doi: 10.1037/0012-1649.17.6.809

External links

Wikimedia Commons has media related to: Maslow's hierarchy of needs
Source: http://en.wikipedia.org/wiki/Maslow%27s_hierarchy_of_needs

Continue Reading

Nucleus Accumbens

By on 12th April 2013 in Psychology 0
TwitterFacebookLinkedInGoogle+bufferEmail

 It has been suggested that Nucleus accumbens core and Nucleus accumbens shell be merged into this article. (Discuss) Proposed since January 2013.

The nucleus accumbens (NAcc), also known as the accumbens nucleus or as the nucleus accumbens septi (Latin for nucleus is adjacent to the septum) in the basal forebrain rostral to the preoptic area[1]. It is considered to be a critical component in the brain's pleasure center due to its association with the ventral striatum. The nucleus accumbens and the olfactory tubercle collectively form the ventral striatum, which is part of the basal ganglia.[2]

Each brain hemisphere has its own nucleus accumbens. It is located where the head of the caudate and the anterior portion of the putamen meet just lateral to the septum pellucidum. The nucleus accumbens can be divided into two structures—the nucleus accumbens core and the nucleus accumbens shell. These structures have different morphology and function.

Research has indicated the nucleus accumbens has an important role in reward, pleasure, reinforcement learning, laughter, addiction, aggression, fear, impulsivity and the placebo effect.[3][4][5][6]


Cell types [edit]

The principal neuronal cell type found in the nucleus accumbens is the medium spiny neuron. The neurotransmitter produced by these neurons is gamma-aminobutyric acid (GABA), one of the main inhibitory neurotransmitters of the central nervous system. These neurons are also the main projection or output neurons of the nucleus accumbens.

While 95% of the neurons in the nucleus accumbens are medium spiny GABA-ergic projection neurons, other neuronal types are also found such as large aspiny cholinergic interneurons.

Output and input [edit]

Output [edit]

The output neurons of the nucleus accumbens send axon projections to the basal ganglia and the ventral analog of the globus pallidus, known as the ventral pallidum (VP). The VP, in turn, projects to the medial dorsal nucleus of the dorsal thalamus, which projects to the prefrontal cortex as well as the striatum. Other efferents from the nucleus accumbens include connections with the substantia nigra, and the pontine reticular formation. [7]

Input [edit]

Major inputs to the nucleus accumbens include prefrontal association cortices, basolateral amygdala, and dopaminergic neurons located in the ventral tegmental area (VTA), which connect via the mesolimbic pathway. Thus the nucleus accumbens is often described as one part of a cortico-striato-thalamo-cortical loop.

Dopaminergic input from the VTA is thought to modulate the activity of neurons within the nucleus accumbens. These terminals are also the site of action of highly-addictive drugs such as cocaine and amphetamine, which cause a manifold increase in dopamine levels in the nucleus accumbens.

Another major source of input comes from the CA1 and ventral subiculum of the hippocampus to the dorsomedial area of the Nucleus accumbens. The neurons of the hippocampus have a noteworthy correlation to slight depolarizations of cells in the nucleus accumbens, which makes them more positive and therefore more excitable. The correlated cells of these excited states of the medium spiny neurons in the Nucleus accumbens are shared equally between the subiculum and CA1. The subiculum neurons are found to hyperpolarize (increase negativity) while the CA1 neurons "ripple" (fire > 50 Hz) in order to accomplish this priming. [8]

Research [edit]

Addiction and Drug Use [edit]

Research using microdialysis has shown that the levels of dopamine in the extracellular fluid of the nucleus accumbens increases when rats are injected with addictive drugs such as cocaine, heroin, nicotine, or alcohol. [9] This increase in dopamine is believed to be responsible for the reinforcing effects that later stimulate drug-taking behavior. Functional-imaging studies in humans has shown that environmental cues associated with addictive drugs releases dopamine in the nucleus accumbens. However, when administered methylphenidate drug addicted subjects had a much smaller release of dopamine in this area than non-addicted subjects. These findings suggest the notion that the nucleus accumbens is associated with the beginnings of drug addiction and the dorsal striatum is responsible for the augmentation of the drug habit. [10]

The nucleus accumbens has been targeted by stereotactic surgery for ablation as a treatment in China for alcoholism.[11]

Deep brain stimulation has recently been used to study its effects on drug addiction. Mantione et al. has found that the stimulation of the nucleus accumbens in one subject showed a decrease in nicotine use. [12]

Pleasure and Reinforcement [edit]

Although the nucleus accumbens has traditionally been studied for its role in addiction, it plays an equal role in processing many rewards such as food and sex. The nucleus accumbens is selectively activated during the perception of pleasant, emotionally arousing pictures and during mental imagery of pleasant, emotional scenes.[13][14] A 2005 study found that it is involved in the regulation of emotions induced by music,[15] perhaps consequent to its role in mediating dopamine release. The nucleus accumbens plays a role in rhythmic timing and is considered to be of central importance to the limbic-motor interface (Mogensen).

In the 1950s, James Olds and Peter Milner implanted electrodes into the septal area of the rat and found that the rat chose to press a lever which stimulated it. It continued to prefer this even over stopping to eat or drink. This suggests that the area is the "pleasure center" of the brain and is involved in reinforcement learning. [16] In rats, stimulation of the ventral tegmental area causes the release of dopamine in the nucleus accumbens much in the same way as addictive drugs and natural reinforcers, such as water or food, initiate the release of dopamine in the nucleus accumbens. [17] The same results have been seen in human subjects in functional imaging studies. For example, increased dopamine concentration is seen in the extracellular fluid of the nucleus accumbens when subjects believed they were being given money, and when heterosexual males were presented pictures of attractive women. [18]

Maternal Behavior [edit]

An fMRI study conducted in 2005 found that when mother rats were in the presence of their pups the regions of the brain involved in reinforcement, including the nucleus accumbens, were highly active. [19] Levels of dopamine increase in the nucleus accumbens during maternal behavior, while lesions in this area upset maternal behavior. [20] When human mothers are presented pictures of their children, fMRIs show an increased brain activity in the nucleus accumbens and other reinforcing brain regions and a decrease in activity in areas of the brain involved with negative emotions.

Deep Brain Stimulation [edit]

In April 2007, two research teams reported on having inserted electrodes into the nucleus accumbens in order to use deep brain stimulation to treat severe depression.[21] In 2010 experiments conducted by Bewernick et al. reported that deep brain stimulation of the nucleus accumbens was successful in decreasing depression symptoms in 50% of patients who did not respond to other treatments such as electroconvulsive therapy.[22]

Placebo Effect [edit]

In addition, in July 2007, researcher Jon-Kar Zubieta published findings that the nucleus accumbens is central to the machinery of the placebo effect. His group has confirmed that specific neural circuits and neurotransmitter systems respond to the expectation of benefit during placebo administration and that these expectations induce measurable physiological changes.[23]


Additional images [edit]

  • Dopamine and serotonin

  • MRI coronal slice showing nucleus accumbens outlined in red

  • Sagittal MRI slice with highlighting (red) indicating the nucleus accumbens.

References [edit]

  1. ^ Carlson, Neil R. Physiology of Behavior. 11th ed. Boston: Pearson, 2013. Print.
  2. ^ Nucleus Accumbens
  3. ^ Schwienbacher I, Fendt M, Richardson R, Schnitzler HU (2004). "Temporary inactivation of the nucleus accumbens disrupts acquisition and expression of fear-potentiated startle in rats". Brain Res. 1027 (1–2): 87–93. doi:10.1016/j.brainres.2004.08.037. PMID 15494160. 
  4. ^ The Placebo Effect in the NAC
  5. ^ Dopamine Involved In Aggression - Medical News Today
  6. ^ Basar, Koray, Thibaut Sesia, Henk Groenewegen, Harry W.M. Steinbusch, Veerle Visser-Vandewalle, and Yasin Temel. "Nucleus Accumbens and Impulsivity."Progress in Neurobiology 92.4 (2010): 533-57. Print.
  7. ^ Carlson, Neil R. Physiology of Behavior. 11th ed. Boston: Pearson, 2013. Print.
  8. ^ O'Donnell, P., Goto, Y. (2001). "Synchronous activity in the hippocampus and nucleus accumbens in vivo". J. Neurosci. 21 (4): RC131. PMID 11160416. 
  9. ^ Carlson, Neil R. Physiology of Behavior. 11th ed. Boston: Pearson, 2013. Print
  10. ^ Carlson, Neil R. Physiology of Behavior. 11th ed. Boston: Pearson, 2013. Print
  11. ^ Wu HM, Wang XL, Chang CW, Li N, Gao L, Geng N, Ma JH, Zhao W, Gao GD. (2010). Preliminary findings in ablating the nucleus accumbens using stereotactic surgery for alleviating psychological dependence on alcohol. Neurosci Lett. 473: 77–81 doi:10.1016/j.neulet.2010.02.019 PMID 20156524
  12. ^ Mantione, M., van de Brink, W., Schuurman, P. R., and Denys, D. Smoking cessation and weight loss after chronic deep brain stimulation of the nucleus accumbens: Therapeutic and research implications: Case report. Neurosurgery, 2010, 66, E2018.
  13. ^ Costa, VD, Lang, PJ, Sabatinelli, D, Bradley MM, and Versace, F (2010). "Emotional imagery: Assessing pleasure and arousal in the brain's reward circuitry". Human Brain Mapping 31 (9): 1446–1457. doi:10.1002/hbm.20948. PMID 20127869. 
  14. ^ Sabatinelli, D, Lang, PJ, Bradley, MM, Costa, VD, and Versace, F (2007). "Pleasure rather than salience activates human nucleus accumbens and medial prefrontal cortex". Journal of Neurophysiology 98 (9): 1374–1379. doi:10.1152/jn.00230.2007. PMID 17596422. 
  15. ^ Menon, Vinod & Levitin, Daniel J. (2005) The rewards of music listening: Response and physiological connectivity of themesolimbic system." NeuroImage 28(1), pp. 175-184
  16. ^ Olds J, Milner P (1954). "Positive reinforcement produced by electrical stimulation of septal area and other regions of rat brain". J Comp Physiol Psychol 47 (6): 419–27. doi:10.1037/h0058775. PMID 13233369.  article
  17. ^ Nakahara, D., Ozaki, N., Miura, Y., Miura, H., et al. Increased dopamine and serotonin metabolism in rat nucleus accumbens produced by intracranial sel-stimulation of medial forebrain bundle as measured by in vivo microdialysis. Brain Research, 1989, 495, 178-181.
  18. ^ Aharon, L., Etcoff, N., Ariely, D., CHabris, C. F., et al. Beautiful faces have variable reward value: fMRI and behavioral evidence. Neuron 2001, 32, 357-551.
  19. ^ Ferris, C.F., Kulkarni, P., Sullivan, J.M., Harder, J.A., et al. Pup sucking is more rewarding than cocaine: Evidence from functional magnetic resonance imaging and three-dimensional computational analysis. Journal of Neuroscience, 2005, 25, 149-156.
  20. ^ Numan, M. Motivational systems and the neural circuitry of maternal behavior in the rat. Developmental Psychobiology, 2007, 49, 12-21.
  21. ^ Brain Electrodes Help Treat Depression, Technology Review, 26 April 2007
  22. ^ Bewernick, B. H., Hurlemann, R., Matusch, A., et al. Nucleus accumbens deep brain stimulation decreases ratings of depression and anciety in treatment-resistant depresssion. Biological Psychiatry, 2009, 67, 110-116.
  23. ^ http://www.eurekalert.org/pub_releases/2007-07/cp-brc071607.php Brain region central to placebo effect identified

External links [edit]

Wikimedia Commons has media related to: Nucleus accumbens


Basal ganglia
Other
Rhinencephalon
Other basal forebrain
Archicortex:
Hippocampal formation/
Hippocampus anatomy
Acetylcholine
BA/M
AA
Source: http://en.wikipedia.org/wiki/Nucleus_accumbens

Continue Reading

Content Strategy

By on 12th February 2013 in Marketing 0
TwitterFacebookLinkedInGoogle+bufferEmail

Content strategy refers to the planning, development, and management of informational content—written or in other media. The term is particularly common in web development since the late 1990s. It is recognized as a field in user experience design but also draws interest from adjacent communities such as content management, business analysis, and technical communication.

Definitions [edit]

Content strategy has been described as "…the practice of planning the content creation, delivery, and governance."[1] and "a repeatable system that defines the entire editorial content development process for a website development project." [2]

In her 2007 article, "Content Strategy: The Philosophy of Data," Rachel Lovinger described the goal of content strategy as using "…words and data to create unambiguous content that supports meaningful, interactive experiences." Here, she also provided the analogy "…content strategy is to copywriting as information architecture is to design."[3]

Many organizations and individuals tend to confuse content strategists with editors. Yet, content strategy is "about more than just the written word," according to Washington State University assistant professor Brett Atwood. For example, Atwood indicates that a practitioner needs to also "consider how content might be re-distributed and/or re-purposed in other channels of delivery." [4]

Further, content strategists should strive to achieve content that is readable and understandable, findable, actionable and shareable in all of its various forms.[5]

The purpose of content strategy has also been described as achieving business goals by maximizing the impact of content.[6]

It has also been proposed that the content strategist performs the role of a tastemaker or curator. A museum curator sifts through the mass of content and identifies key pieces that can be juxtaposed against each another to create meaning and spur excitement. In her 2009 article, Erin Scime states that the content strategist as digital curator, "…approaches a business’s content as a medium that needs to be strategically selected and placed to engage the audience, convey a message, and inspire action."[7]

The definition of digital content itself has been changing with respect to media and publishing trends. Three key components of content are text, as touched on above, as well as photo and video. Photos can be displayed on publisher sites in multiple fashions. Slide shows, click to enlarge, montages, and Pinterest-style are a few vehicles in which to deliver photography to the user. Videos can appear as a click to open a pop-up, or an embedded video player on the page itself. Choosing the still-image and thumbnails associated with videos is a content strategist's decision. The display of these elements on social media pages (Facebook walls, Twitter feeds, etc.) also falls within the realm of content strategy.

Practitioners [edit]

An individual who practices content strategy as a discipline is referred to as a content strategist. The perspectives that content strategists bring to content depend strongly on their professional training and education.

For instance, some specialize in content analysis, which roughly describes work with metadata, taxonomy, search engine optimization, and the ways these concepts support content.

Others outline web editorial strategies, guidelines, and tools, which may extend to organizational change management. This form of content strategy may be concerned with developing new forms of content, such as multimedia, or various “presence management” technologies like microblogging.

There is yet another stream of content strategy advancing information architecture goals. In this case, content strategy may only involve writing site copy for new website pages and adapting the content on existing ones. All content strategists are familiar with a wide range of applications and tools, and frequently are responsible for implementing and training individuals to best use them.

Resources [edit]

References [edit]

  1. ^ Kristina Halvorson. "The Discipline of Content Strategy". AListApart.com. 
  2. ^ Sheffield, Richard (2009). “The Web Content Strategist’s Bible”, p.35. Cluefox Publishing, Atlanta. ISBN 978-1-4414-8262-4
  3. ^ Rachel Lovinger. "Content Strategy: The Philosophy of Data". Boxes & Arrows. 
  4. ^ Brett Atwood. "Case Study: Content Strategy and Second Life". crowdcircles.com. 
  5. ^ Content Marketing Institute. "Creating Valuable Content: An Essential Checklist". contentmarketinginstitute.com. 
  6. ^ Contentini. "Content Strategists: What Do They Do?". contentini.com. 
  7. ^ Erin Scime (8 December 2009). "The Content Strategist as Digital Curator". A List Apart. 
Source: http://en.wikipedia.org/wiki/Content_strategy

Continue Reading

Search Engine Optimisation

By on 28th January 2013 in Marketing 0
TwitterFacebookLinkedInGoogle+bufferEmail

Page semi-protected
"SEO" redirects here. For other uses, see SEO (disambiguation).
Internet marketing
Search engine marketing
Display advertising
Affiliate marketing
Mobile advertising

Search engine optimization (SEO) is the process of affecting the visibility of a website or a web page in a search engine's "natural" or un-paid ("organic") search results. In general, the earlier (or higher ranked on the search results page), and more frequently a site appears in the search results list, the more visitors it will receive from the search engine's users. SEO may target different kinds of search, including image search, local search, video search, academic search,[1] news search and industry-specific vertical search engines.

As an Internet marketing strategy, SEO considers how search engines work, what people search for, the actual search terms or keywords typed into search engines and which search engines are preferred by their targeted audience. Optimizing a website may involve editing its content, HTML and associated coding to both increase its relevance to specific keywords and to remove barriers to the indexing activities of search engines. Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic.

The plural of the abbreviation SEO can also refer to "search engine optimizers," those who provide SEO services.

History

Webmasters and content providers began optimizing sites for search engines in the mid-1990s, as the first search engines were cataloging the early Web. Initially, all webmasters needed to do was to submit the address of a page, or URL, to the various engines which would send a "spider" to "crawl" that page, extract links to other pages from it, and return information found on the page to be indexed.[2] The process involves a search engine spider downloading a page and storing it on the search engine's own server, where a second program, known as an indexer, extracts various information about the page, such as the words it contains and where these are located, as well as any weight for specific words, and all links the page contains, which are then placed into a scheduler for crawling at a later date.

Site owners started to recognize the value of having their sites highly ranked and visible in search engine results, creating an opportunity for both white hat and black hat SEO practitioners. According to industry analyst Danny Sullivan, the phrase "search engine optimization" probably came into use in 1997.[3] The first documented use of the term Search Engine Optimization was John Audette and his company Multimedia Marketing Group as documented by a web page from the MMG site from August, 1997.[4]

Early versions of search algorithms relied on webmaster-provided information such as the keyword meta tag, or index files in engines like ALIWEB. Meta tags provide a guide to each page's content. Using meta data to index pages was found to be less than reliable, however, because the webmaster's choice of keywords in the meta tag could potentially be an inaccurate representation of the site's actual content. Inaccurate, incomplete, and inconsistent data in meta tags could and did cause pages to rank for irrelevant searches.[5][dubious – discuss] Web content providers also manipulated a number of attributes within the HTML source of a page in an attempt to rank well in search engines.[6]

By relying so much on factors such as keyword density which were exclusively within a webmaster's control, early search engines suffered from abuse and ranking manipulation. To provide better results to their users, search engines had to adapt to ensure their results pages showed the most relevant search results, rather than unrelated pages stuffed with numerous keywords by unscrupulous webmasters. Since the success and popularity of a search engine is determined by its ability to produce the most relevant results to any given search, allowing those results to be false would turn users to find other search sources. Search engines responded by developing more complex ranking algorithms, taking into account additional factors that were more difficult for webmasters to manipulate. Graduate students at Stanford University, Larry Page and Sergey Brin, developed "Backrub," a search engine that relied on a mathematical algorithm to rate the prominence of web pages. The number calculated by the algorithm, PageRank, is a function of the quantity and strength of inbound links.[7] PageRank estimates the likelihood that a given page will be reached by a web user who randomly surfs the web, and follows links from one page to another. In effect, this means that some links are stronger than others, as a higher PageRank page is more likely to be reached by the random surfer.

Page and Brin founded Google in 1998. Google attracted a loyal following among the growing number of Internet users, who liked its simple design.[8] Off-page factors (such as PageRank and hyperlink analysis) were considered as well as on-page factors (such as keyword frequency, meta tags, headings, links and site structure) to enable Google to avoid the kind of manipulation seen in search engines that only considered on-page factors for their rankings. Although PageRank was more difficult to game, webmasters had already developed link building tools and schemes to influence the Inktomi search engine, and these methods proved similarly applicable to gaming PageRank. Many sites focused on exchanging, buying, and selling links, often on a massive scale. Some of these schemes, or link farms, involved the creation of thousands of sites for the sole purpose of link spamming.[9]

By 2004, search engines had incorporated a wide range of undisclosed factors in their ranking algorithms to reduce the impact of link manipulation. In June 2007, The New York Times' Saul Hansell stated Google ranks sites using more than 200 different signals.[10] The leading search engines, Google, Bing, and Yahoo, do not disclose the algorithms they use to rank pages. Some SEO practitioners have studied different approaches to search engine optimization, and have shared their personal opinions[11] Patents related to search engines can provide information to better understand search engines.[12]

In 2005, Google began personalizing search results for each user. Depending on their history of previous searches, Google crafted results for logged in users.[13] In 2008, Bruce Clay said that "ranking is dead" because of personalized search. He opined that it would become meaningless to discuss how a website ranked, because its rank would potentially be different for each user and each search.[14]

In 2007, Google announced a campaign against paid links that transfer PageRank.[15] On June 15, 2009, Google disclosed that they had taken measures to mitigate the effects of PageRank sculpting by use of the nofollow attribute on links. Matt Cutts, a well-known software engineer at Google, announced that Google Bot would no longer treat nofollowed links in the same way, in order to prevent SEO service providers from using nofollow for PageRank sculpting.[16] As a result of this change the usage of nofollow leads to evaporation of pagerank. In order to avoid the above, SEO engineers developed alternative techniques that replace nofollowed tags with obfuscated Javascript and thus permit PageRank sculpting. Additionally several solutions have been suggested that include the usage of iframes, Flash and Javascript.[17]

In December 2009, Google announced it would be using the web search history of all its users in order to populate search results.[18]

Google Instant, real-time-search, was introduced in late 2010 in an attempt to make search results more timely and relevant. Historically site administrators have spent months or even years optimizing a website to increase search rankings. With the growth in popularity of social media sites and blogs the leading engines made changes to their algorithms to allow fresh content to rank quickly within the search results.[19]

In February 2011, Google announced the "Panda update, which penalizes websites containing content duplicated from other websites and sources. Historically websites have copied content from one another and benefited in search engine rankings by engaging in this practice, however Google implemented a new system which punishes sites whose content is not unique.[20]

In April 2012, Google launched the Google Penguin update the goal of which was to penalise websites that used manipulative techniques to improve their rankings on the search engine.[21]

Relationship with search engines

Yahoo and Google offices

By 1997, search engines recognized that webmasters were making efforts to rank well in their search engines, and that some webmasters were even manipulating their rankings in search results by stuffing pages with excessive or irrelevant keywords. Early search engines, such as Altavista and Infoseek, adjusted their algorithms in an effort to prevent webmasters from manipulating rankings.[22]

In 2005, an annual conference, AIRWeb, Adversarial Information Retrieval on the Web was created to bring together practitioners and researchers concerned with search engine optimisation and related topics.[23]

Companies that employ overly aggressive techniques can get their client websites banned from the search results. In 2005, the Wall Street Journal reported on a company, Traffic Power, which allegedly used high-risk techniques and failed to disclose those risks to its clients.[24]Wired magazine reported that the same company sued blogger and SEO Aaron Wall for writing about the ban.[25] Google's Matt Cutts later confirmed that Google did in fact ban Traffic Power and some of its clients.[26]

Some search engines have also reached out to the SEO industry, and are frequent sponsors and guests at SEO conferences, chats, and seminars. Major search engines provide information and guidelines to help with site optimization.[27][28] Google has a Sitemaps program to help webmasters learn if Google is having any problems indexing their website and also provides data on Google traffic to the website.[29]Bing Webmaster Tools provides a way for webmasters to submit a sitemap and web feeds, allows users to determine the crawl rate, and track the web pages index status.

Methods

Getting indexed

The leading search engines, such as Google, Bing and Yahoo!, use crawlers to find pages for their algorithmic search results. Pages that are linked from other search engine indexed pages do not need to be submitted because they are found automatically. Some search engines, notably Yahoo!, operate a paid submission service that guarantee crawling for either a set fee or cost per click.[30] Such programs usually guarantee inclusion in the database, but do not guarantee specific ranking within the search results.[31] Two major directories, the Yahoo Directory and the Open Directory Project both require manual submission and human editorial review.[32] Google offers Google Webmaster Tools, for which an XML Sitemap feed can be created and submitted for free to ensure that all pages are found, especially pages that are not discoverable by automatically following links.[33]

Search engine crawlers may look at a number of different factors when crawling a site. Not every page is indexed by the search engines. Distance of pages from the root directory of a site may also be a factor in whether or not pages get crawled.[34]

Preventing crawling

Main article: Robots Exclusion Standard

To avoid undesirable content in the search indexes, webmasters can instruct spiders not to crawl certain files or directories through the standard robots.txt file in the root directory of the domain. Additionally, a page can be explicitly excluded from a search engine's database by using a meta tag specific to robots. When a search engine visits a site, the robots.txt located in the root directory is the first file crawled. The robots.txt file is then parsed, and will instruct the robot as to which pages are not to be crawled. As a search engine crawler may keep a cached copy of this file, it may on occasion crawl pages a webmaster does not wish crawled. Pages typically prevented from being crawled include login specific pages such as shopping carts and user-specific content such as search results from internal searches. In March 2007, Google warned webmasters that they should prevent indexing of internal search results because those pages are considered search spam.[35]

Increasing prominence

A variety of methods can increase the prominence of a webpage within the search results. Cross linking between pages of the same website to provide more links to most important pages may improve its visibility.[36] Writing content that includes frequently searched keyword phrase, so as to be relevant to a wide variety of search queries will tend to increase traffic.[36] Updating content so as to keep search engines crawling back frequently can give additional weight to a site. Adding relevant keywords to a web page's meta data, including the title tag and meta description, will tend to improve the relevancy of a site's search listings, thus increasing traffic. URL normalization of web pages accessible via multiple urls, using the canonical link element[37] or via 301 redirects can help make sure links to different versions of the url all count towards the page's link popularity score.

White hat versus black hat techniques

SEO techniques can be classified into two broad categories: techniques that search engines recommend as part of good design, and those techniques of which search engines do not approve. The search engines attempt to minimize the effect of the latter, among them spamdexing. Industry commentators have classified these methods, and the practitioners who employ them, as either white hat SEO, or black hat SEO.[38] White hats tend to produce results that last a long time, whereas black hats anticipate that their sites may eventually be banned either temporarily or permanently once the search engines discover what they are doing.[39]

An SEO technique is considered white hat if it conforms to the search engines' guidelines and involves no deception. As the search engine guidelines[27][28][40] are not written as a series of rules or commandments, this is an important distinction to note. White hat SEO is not just about following guidelines, but is about ensuring that the content a search engine indexes and subsequently ranks is the same content a user will see. White hat advice is generally summed up as creating content for users, not for search engines, and then making that content easily accessible to the spiders, rather than attempting to trick the algorithm from its intended purpose. White hat SEO is in many ways similar to web development that promotes accessibility,[41] although the two are not identical.

Black hat SEO attempts to improve rankings in ways that are disapproved of by the search engines, or involve deception. One black hat technique uses text that is hidden, either as text colored similar to the background, in an invisible div, or positioned off screen. Another method gives a different page depending on whether the page is being requested by a human visitor or a search engine, a technique known as cloaking.

Search engines may penalize sites they discover using black hat methods, either by reducing their rankings or eliminating their listings from their databases altogether. Such penalties can be applied either automatically by the search engines' algorithms, or by a manual site review. One example was the February 2006 Google removal of both BMW Germany and Ricoh Germany for use of deceptive practices.[42] Both companies, however, quickly apologized, fixed the offending pages, and were restored to Google's list.[43]

As a marketing strategy

SEO is not an appropriate strategy for every website, and other Internet marketing strategies can be more effective, depending on the site operator's goals.[44] A successful Internet marketing campaign may also depend upon building high quality web pages to engage and persuade, setting up analytics programs to enable site owners to measure results, and improving a site's conversion rate.[45]

SEO may generate an adequate return on investment. However, search engines are not paid for organic search traffic, their algorithms change, and there are no guarantees of continued referrals. Due to this lack of guarantees and certainty, a business that relies heavily on search engine traffic can suffer major losses if the search engines stop sending visitors.[46] Search engines can change their algorithms, impacting a website's placement, possibly resulting in a serious loss of traffic. According to Google's CEO, Eric Schmidt, in 2010, Google made over 500 algorithm changes – almost 1.5 per day.[47] It is considered wise business practice for website operators to liberate themselves from dependence on search engine traffic.[48]

International markets

Optimization techniques are highly tuned to the dominant search engines in the target market. The search engines' market shares vary from market to market, as does competition. In 2003, Danny Sullivan stated that Google represented about 75% of all searches.[49] In markets outside the United States, Google's share is often larger, and Google remains the dominant search engine worldwide as of 2007.[50] As of 2006, Google had an 85–90% market share in Germany.[51] While there were hundreds of SEO firms in the US at that time, there were only about five in Germany.[51] As of June 2008, the marketshare of Google in the UK was close to 90% according to Hitwise.[52] That market share is achieved in a number of countries.

As of 2009, there are only a few large markets where Google is not the leading search engine. In most cases, when Google is not leading in a given market, it is lagging behind a local player. The most notable example markets are China, Japan, South Korea, Russia and the Czech Republic where respectively Baidu, Yahoo! Japan, Naver, Yandex and Seznam are market leaders.

Successful search optimization for international markets may require professional translation of web pages, registration of a domain name with a top level domain in the target market, and web hosting that provides a local IP address. Otherwise, the fundamental elements of search optimization are essentially the same, regardless of language.[51]

Legal precedents

On October 17, 2002, SearchKing filed suit in the United States District Court, Western District of Oklahoma, against the search engine Google. SearchKing's claim was that Google's tactics to prevent spamdexing constituted a tortious interference with contractual relations. On May 27, 2003, the court granted Google's motion to dismiss the complaint because SearchKing "failed to state a claim upon which relief may be granted."[53][54]

In March 2006, KinderStart filed a lawsuit against Google over search engine rankings. Kinderstart's website was removed from Google's index prior to the lawsuit and the amount of traffic to the site dropped by 70%. On March 16, 2007 the United States District Court for the Northern District of California (San Jose Division) dismissed KinderStart's complaint without leave to amend, and partially granted Google's motion for Rule 11 sanctions against KinderStart's attorney, requiring him to pay part of Google's legal expenses.[55][56]

Notes

  1. ^ Beel, Jöran and Gipp, Bela and Wilde, Erik (2010). "Academic Search Engine Optimization (ASEO): Optimizing Scholarly Literature for Google Scholar and Co.". Journal of Scholarly Publishing. pp. 176–190. Retrieved April 18, 2010. 
  2. ^ Brian Pinkerton. "Finding What People Want: Experiences with the WebCrawler" (PDF). The Second International WWW Conference Chicago, USA, October 17–20, 1994. Retrieved May 7, 2007. 
  3. ^ Danny Sullivan (June 14, 2004). "Who Invented the Term "Search Engine Optimization"?". Search Engine Watch. Retrieved May 14, 2007.  See Google groups thread.
  4. ^ (Document Number 19970801004204) "Documentation of Who Invented SEO at the Internet Way Back Machine". Internet Way Back Machine. Archived from (Document Number 19970801004204) the original on August 1, 1997. [who?]
  5. ^ Cory Doctorow (August 26, 2001). "Metacrap: Putting the torch to seven straw-men of the meta-utopia". e-LearningGuru. Archived from the original on April 9, 2007. Retrieved May 8, 2007. 
  6. ^ Pringle, G., Allison, L., and Dowe, D. (April 1998). "What is a tall poppy among web pages?". Proc. 7th Int. World Wide Web Conference. Retrieved May 8, 2007. 
  7. ^ Brin, Sergey and Page, Larry (1998). "The Anatomy of a Large-Scale Hypertextual Web Search Engine". Proceedings of the seventh international conference on World Wide Web. pp. 107–117. Retrieved May 8, 2007. 
  8. ^ Thompson, Bill (December 19, 2003). "Is Google good for you?". BBC News. Retrieved May 16, 2007. 
  9. ^ Zoltan Gyongyi and Hector Garcia-Molina (2005). "Link Spam Alliances" (PDF). Proceedings of the 31st VLDB Conference, Trondheim, Norway. Retrieved May 9, 2007. 
  10. ^ Hansell, Saul (June 3, 2007). "Google Keeps Tweaking Its Search Engine". New York Times. Retrieved June 6, 2007. 
  11. ^ Danny Sullivan (September 29, 2005). "Rundown On Search Ranking Factors". Search Engine Watch. Retrieved May 8, 2007. 
  12. ^ Christine Churchill (November 23, 2005). "Understanding Search Engine Patents". Search Engine Watch. Retrieved May 8, 2007. 
  13. ^ "Google Personalized Search Leaves Google Labs". searchenginewatch.com. Search Engine Watch. Retrieved September 5, 2009. 
  14. ^ "Will Personal Search Turn SEO On Its Ear? | WebProNews". www.webpronews.com. Retrieved September 5, 2009. [non-primary source needed]
  15. ^ "8 Things We Learned About Google PageRank". www.searchenginejournal.com. Retrieved August 17, 2009. 
  16. ^ "PageRank sculpting". Matt Cutts. Retrieved January 12, 2010. 
  17. ^ "Google Loses "Backwards Compatibility" On Paid Link Blocking & PageRank Sculpting". searchengineland.com. Retrieved August 17, 2009. 
  18. ^ "Personalized Search for everyone". Google. Retrieved December 14, 2009. 
  19. ^ "Relevance Meets Real Time Web". Google Blog. 
  20. ^ "Google Search Quality Updates". Google Blog. 
  21. ^ "What You Need to Know About Google's Penguin Update". Inc.com. 
  22. ^ Laurie J. Flynn (November 11, 1996). "Desperately Seeking Surfers". New York Times. Retrieved May 9, 2007. 
  23. ^ "AIRWeb". Adversarial Information Retrieval on the Web, annual conference. Retrieved Oct 4, 2012. 
  24. ^ David Kesmodel (September 22, 2005). "Sites Get Dropped by Search Engines After Trying to 'Optimize' Rankings". Wall Street Journal. Retrieved July 30, 2008. 
  25. ^ Adam L. Penenberg (September 8, 2005). "Legal Showdown in Search Fracas". Wired Magazine. Retrieved May 9, 2007. 
  26. ^ Matt Cutts (February 2, 2006). "Confirming a penalty". mattcutts.com/blog. Retrieved May 9, 2007. 
  27. ^ a b "Google's Guidelines on Site Design". google.com. Retrieved April 18, 2007. 
  28. ^ a b "Guidelines for Successful Indexing". bing.com. Retrieved September 7, 2011. 
  29. ^ "Sitemaps". google.com. Retrieved May 4, 2012. 
  30. ^ "Submitting To Search Crawlers: Google, Yahoo, Ask & Microsoft's Live Search". Search Engine Watch. March 12, 2007. Retrieved May 15, 2007. 
  31. ^ "Search Submit". searchmarketing.yahoo.com. Retrieved May 9, 2007. [dead link]
  32. ^ "Submitting To Directories: Yahoo & The Open Directory". Search Engine Watch. March 12, 2007. Retrieved May 15, 2007. 
  33. ^ "What is a Sitemap file and why should I have one?". google.com. Retrieved March 19, 2007. 
  34. ^ Cho, J., Garcia-Molina, H. (1998). "Efficient crawling through URL ordering". Proceedings of the seventh conference on World Wide Web, Brisbane, Australia. Retrieved May 9, 2007. 
  35. ^ "Newspapers Amok! New York Times Spamming Google? LA Times Hijacking Cars.com?". Search Engine Land. May 8, 2007. Retrieved May 9, 2007. 
  36. ^ a b "The Most Important SEO Strategy". clickz.com. ClickZ. Retrieved April 18, 2010. 
  37. ^ "Bing – Partnering to help solve duplicate content issues – Webmaster Blog – Bing Community". www.bing.com. Retrieved October 30, 2009. 
  38. ^ Andrew Goodman. "Search Engine Showdown: Black hats vs. White hats at SES". SearchEngineWatch. Retrieved May 9, 2007. 
  39. ^ Jill Whalen (November 16, 2004). "Black Hat/White Hat Search Engine Optimization". searchengineguide.com. Retrieved May 9, 2007. 
  40. ^ "What's an SEO? Does Google recommend working with companies that offer to make my site Google-friendly?". google.com. Retrieved April 18, 2007. 
  41. ^ Andy Hagans (November 8, 2005). "High Accessibility Is Effective Search Engine Optimization". A List Apart. Retrieved May 9, 2007. 
  42. ^ Matt Cutts (February 4, 2006). "Ramping up on international webspam". mattcutts.com/blog. Retrieved May 9, 2007. 
  43. ^ Matt Cutts (February 7, 2006). "Recent reinclusions". mattcutts.com/blog. Retrieved May 9, 2007. 
  44. ^ "What SEO Isn't". blog.v7n.com. June 24, 2006. Retrieved May 16, 2007. 
  45. ^ Melissa Burdon (March 13, 2007). "The Battle Between Search Engine Optimization and Conversion: Who Wins?". Grok.com. Retrieved May 9, 2007. 
  46. ^ Andy Greenberg (April 30, 2007). "Condemned To Google Hell". Forbes. Archived from the original on May 2, 2007. Retrieved May 9, 2007. 
  47. ^ Matt McGee (September 21, 2011). "Schmidt's testimony reveals how Google tests alorithm changes". 
  48. ^ Jakob Nielsen (January 9, 2006). "Search Engines as Leeches on the Web". useit.com. Retrieved May 14, 2007. 
  49. ^ Graham, Jefferson (August 26, 2003). "The search engine that could". USA Today. Retrieved May 15, 2007. 
  50. ^ Greg Jarboe (February 22, 2007). "Stats Show Google Dominates the International Search Landscape". Search Engine Watch. Retrieved May 15, 2007. 
  51. ^ a b c Mike Grehan (April 3, 2006). "Search Engine Optimizing for Europe". Click. Retrieved May 14, 2007. 
  52. ^ Jack Schofield (June 10, 2008). "Google UK closes in on 90% market share". London: Guardian. Retrieved June 10, 2008. 
  53. ^ "Search King, Inc. v. Google Technology, Inc., CIV-02-1457-M" (PDF). docstoc.com. May 27, 2003. Retrieved May 23, 2008. 
  54. ^ Stefanie Olsen (May 30, 2003). "Judge dismisses suit against Google". CNET. Retrieved May 10, 2007. 
  55. ^ "Technology & Marketing Law Blog: KinderStart v. Google Dismissed—With Sanctions Against KinderStart's Counsel". blog.ericgoldman.org. Retrieved June 23, 2008. 
  56. ^ "Technology & Marketing Law Blog: Google Sued Over Rankings—KinderStart.com v. Google". blog.ericgoldman.org. Retrieved June 23, 2008. 

External links

Sound-icon.svg
Search engine optimization
Exclusion standards
Related marketing topics
Search marketing related topics
Search engine spam
Linking
Other
Source: http://en.wikipedia.org/wiki/Search_engine_optimization

Continue Reading

Human-Computer Interaction

By on 17th January 2013 in Psychology 0
TwitterFacebookLinkedInGoogle+bufferEmail

Human use of computers is a major focus of the field of HCI

Human–computer Interaction (HCI) involves the study, planning, and design of the interaction between people (users) and computers. It is often regarded as the intersection of computer science, behavioral sciences, design and several other fields of study. The term was popularized by Card, Moran, and Newell in their seminal 1983 book, "The Psychology of Human-Computer Interaction", although the authors first used the term in 1980,[1] and the first known use was in 1975.[2] The term connotes that, unlike other tools with only limited uses (such as a hammer, useful for driving nails, but not much else), a computer has many affordances for use and this takes place in an open-ended dialog between the user and the computer.

Because human–computer interaction studies a human and a machine in conjunction, it draws from supporting knowledge on both the machine and the human side. On the machine side, techniques in computer graphics, operating systems, programming languages, and development environments are relevant. On the human side, communication theory, graphic and industrial design disciplines, linguistics, social sciences, cognitive psychology, and human factors such as computer user satisfaction are relevant. Engineering and design methods are also relevant. Due to the multidisciplinary nature of HCI, people with different backgrounds contribute to its success. HCI is also sometimes referred to as man–machine interaction (MMI) or computer–human interaction (CHI).

Attention to human-machine interaction is important because poorly designed human-machine interfaces can lead to many unexpected problems. A classic example of this is the Three Mile Island accident, a nuclear meltdown accident, where investigations concluded that the design of the human–machine interface was at least partially responsible for the disaster.[3][4][5] Similarly, accidents in aviation have resulted from manufacturers' decisions to use non-standard flight instrument and/or throttle quadrant layouts: even though the new designs were proposed to be superior in regards to basic human–machine interaction, pilots had already ingrained the "standard" layout and thus the conceptually good idea actually had undesirable results.

Goals [edit]

Question book-new.svg
 This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (February 2013)

A basic goal of HCI is to improve the interactions between users and computers by making computers more usable and receptive to the user's needs. Specifically, HCI is concerned with:

  • Methodologies and processes for designing interfaces (i.e., given a task and a class of users, design the best possible interface within given constraints, optimizing for a desired property such as learnability or efficiency of use)
  • Methods for implementing interfaces (e.g. software toolkits and libraries; efficient algorithms)
  • Techniques for evaluating and comparing interfaces
  • Developing new interfaces and interaction techniques
  • Developing descriptive and predictive models and theories of interaction

A long term goal of HCI is to design systems that minimize the barrier between the human's cognitive model of what they want to accomplish and the computer's understanding of the user's task.

Professional practitioners in HCI are usually designers concerned with the practical application of design methodologies to real-world problems. Their work often revolves around designing graphical user interfaces and web interfaces.

Researchers in HCI are interested in developing new design methodologies, experimenting with new hardware devices, prototyping new software systems, exploring new paradigms for interaction, and developing models and theories of interaction.

Differences with related fields [edit]

Question book-new.svg
 This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (February 2013)

HCI differs from human factors (or ergonomics) as HCI focuses more on users working specifically with computers, rather than other kinds of machines or designed artifacts. There is also a focus in HCI on how to implement the computer software and hardware mechanisms to support human–computer interaction. Thus, human factors is a broader term; HCI could be described as the human factors of computers – although some experts try to differentiate these areas.

HCI also differs from human factors in that there is less of a focus on repetitive work-oriented tasks and procedures, and much less emphasis on physical stress and the physical form or industrial design of the user interface, such as keyboards and mouse devices.

Three areas of study have substantial overlap with HCI even as the focus of inquiry shifts. In the study of personal information management (PIM), human interactions with the computer are placed in a larger informational context – people may work with many forms of information, some computer-based, many not (e.g., whiteboards, notebooks, sticky notes, refrigerator magnets) in order to understand and effect desired changes in their world. In computer-supported cooperative work (CSCW), emphasis is placed on the use of computing systems in support of the collaborative work of a group of people. The principles of human interaction management (HIM) extend the scope of CSCW to an organizational level and can be implemented without use of computer systems.

Design principles [edit]

When evaluating a current user interface, or designing a new user interface, it is important to keep in mind the following experimental design principles:

  • Early focus on user(s) and task(s): Establish how many users are needed to perform the task(s) and determine who the appropriate users should be; someone who has never used the interface, and will not use the interface in the future, is most likely not a valid user. In addition, define the task(s) the users will be performing and how often the task(s) need to be performed.
  • Empirical measurement: Test the interface early on with real users who come in contact with the interface on an everyday basis. Keep in mind that results may vary with the performance level of the user and may not be an accurate depiction of the typical human-computer interaction. Establish quantitative usability specifics such as: the number of users performing the task(s), the time to complete the task(s), and the number of errors made during the task(s).
  • Iterative design: After determining the users, tasks, and empirical measurements to include, perform the following iterative design steps:
  1. Design the user interface
  2. Test
  3. Analyze results
  4. Repeat

Repeat the iterative design process until a sensible, user-friendly interface is created.[6]

Design methodologies [edit]

A number of diverse methodologies outlining techniques for human–computer interaction design have emerged since the rise of the field in the 1980s. Most design methodologies stem from a model for how users, designers, and technical systems interact. Early methodologies, for example, treated users' cognitive processes as predictable and quantifiable and encouraged design practitioners to look to cognitive science results in areas such as memory and attention when designing user interfaces. Modern models tend to focus on a constant feedback and conversation between users, designers, and engineers and push for technical systems to be wrapped around the types of experiences users want to have, rather than wrapping user experience around a completed system.

  • Activity theory: used in HCI to define and study the context in which human interactions with computers take place. Activity theory provides a framework to reason about actions in these contexts, analytical tools with the format of checklists of items that researchers should consider, and informs design of interactions from an activity-centric perspective.[7]
  • User-centered design: user-centered design (UCD) is a modern, widely practiced design philosophy rooted in the idea that users must take center-stage in the design of any computer system. Users, designers and technical practitioners work together to articulate the wants, needs and limitations of the user and create a system that addresses these elements. Often, user-centered design projects are informed by ethnographic studies of the environments in which users will be interacting with the system. This practice is similar but not identical to participatory design, which emphasizes the possibility for end-users to contribute actively through shared design sessions and workshops.
  • Principles of user interface design: these are seven principles of user interface design that may be considered at any time during the design of a user interface in any order: tolerance, simplicity, visibility, affordance, consistency, structure and feedback.[8]

Display designs [edit]

Displays are human-made artifacts designed to support the perception of relevant system variables and to facilitate further processing of that information. Before a display is designed, the task that the display is intended to support must be defined (e.g. navigating, controlling, decision making, learning, entertaining, etc.). A user or operator must be able to process whatever information that a system generates and displays; therefore, the information must be displayed according to principles in a manner that will support perception, situation awareness, and understanding.

Thirteen principles of display design [edit]

Christopher Wickens et al. defined 13 principles of display design in their book An Introduction to Human Factors Engineering.[9]

These principles of human perception and information processing can be utilized to create an effective display design. A reduction in errors, a reduction in required training time, an increase in efficiency, and an increase in user satisfaction are a few of the many potential benefits that can be achieved through utilization of these principles.

Certain principles may not be applicable to different displays or situations. Some principles may seem to be conflicting, and there is no simple solution to say that one principle is more important than another. The principles may be tailored to a specific design or situation. Striking a functional balance among the principles is critical for an effective design.[10]

Perceptual principles [edit]

1. Make displays legible (or audible). A display’s legibility is critical and necessary for designing a usable display. If the characters or objects being displayed cannot be discernible, then the operator cannot effectively make use of them.

2. Avoid absolute judgment limits. Do not ask the user to determine the level of a variable on the basis of a single sensory variable (e.g. color, size, loudness). These sensory variables can contain many possible levels.

3. Top-down processing. Signals are likely perceived and interpreted in accordance with what is expected based on a user’s past experience. If a signal is presented contrary to the user’s expectation, more physical evidence of that signal may need to be presented to assure that it is understood correctly.

4. Redundancy gain. If a signal is presented more than once, it is more likely that it will be understood correctly. This can be done by presenting the signal in alternative physical forms (e.g. color and shape, voice and print, etc.), as redundancy does not imply repetition. A traffic light is a good example of redundancy, as color and position are redundant.

5. Similarity causes confusion: Use discriminable elements. Signals that appear to be similar will likely be confused. The ratio of similar features to different features causes signals to be similar. For example, A423B9 is more similar to A423B8 than 92 is to 93. Unnecessary similar features should be removed and dissimilar features should be highlighted.

Mental model principles [edit]

6. Principle of pictorial realism. A display should look like the variable that it represents (e.g. high temperature on a thermometer shown as a higher vertical level). If there are multiple elements, they can be configured in a manner that looks like it would in the represented environment.

7. Principle of the moving part. Moving elements should move in a pattern and direction compatible with the user’s mental model of how it actually moves in the system. For example, the moving element on an altimeter should move upward with increasing altitude.

Principles based on attention [edit]

8. Minimizing information access cost. When the user’s attention is diverted from one location to another to access necessary information, there is an associated cost in time or effort. A display design should minimize this cost by allowing for frequently accessed sources to be located at the nearest possible position. However, adequate legibility should not be sacrificed to reduce this cost.

9. Proximity compatibility principle. Divided attention between two information sources may be necessary for the completion of one task. These sources must be mentally integrated and are defined to have close mental proximity. Information access costs should be low, which can be achieved in many ways (e.g. proximity, linkage by common colors, patterns, shapes, etc.). However, close display proximity can be harmful by causing too much clutter.

10. Principle of multiple resources. A user can more easily process information across different resources. For example, visual and auditory information can be presented simultaneously rather than presenting all visual or all auditory information.

Memory principles [edit]

11. Replace memory with visual information: knowledge in the world. A user should not need to retain important information solely in working memory or retrieve it from long-term memory. A menu, checklist, or another display can aid the user by easing the use of their memory. However, the use of memory may sometimes benefit the user by eliminating the need to reference some type of knowledge in the world (e.g. an expert computer operator would rather use direct commands from memory than refer to a manual). The use of knowledge in a user’s head and knowledge in the world must be balanced for an effective design.

12. Principle of predictive aiding. Proactive actions are usually more effective than reactive actions. A display should attempt to eliminate resource-demanding cognitive tasks and replace them with simpler perceptual tasks to reduce the use of the user’s mental resources. This will allow the user to not only focus on current conditions, but also think about possible future conditions. An example of a predictive aid is a road sign displaying the distance from a certain destination.

13. Principle of consistency. Old habits from other displays will easily transfer to support processing of new displays if they are designed in a consistent manner. A user’s long-term memory will trigger actions that are expected to be appropriate. A design must accept this fact and utilize consistency among different displays.

Human–computer interface [edit]

Main article: User interface

The human–computer interface can be described as the point of communication between the human user and the computer. The flow of information between the human and computer is defined as the loop of interaction. The loop of interaction has several aspects to it including:

  • Task environment: The conditions and goals set upon the user.
  • Machine environment: The environment that the computer is connected to, e.g. a laptop in a college student's dorm room.
  • Areas of the interface: Non-overlapping areas involve processes of the human and computer not pertaining to their interaction. Meanwhile, the overlapping areas only concern themselves with the processes pertaining to their interaction.
  • Input flow: The flow of information that begins in the task environment, when the user has some task that requires using their computer.
  • Output: The flow of information that originates in the machine environment.
  • Feedback: Loops through the interface that evaluate, moderate, and confirm processes as they pass from the human through the interface to the computer and back.

Current research [edit]

Question book-new.svg
 This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (October 2010)

Topics in HCI include:

User customization [edit]

End-user development studies how ordinary users could routinely tailor applications to their own needs and use this power to invent new applications based on their understanding of their own domains. With their deeper knowledge of their own knowledge domains, users could increasingly be important sources of new applications at the expense of generic systems programmers (with systems expertise but low domain expertise).

Embedded computation [edit]

Computation is passing beyond computers into every object for which uses can be found. Embedded systems make the environment alive with little computations and automated processes, from computerized cooking appliances to lighting and plumbing fixtures to window blinds to automobile braking systems to greeting cards. To some extent, this development is already taking place. The expected difference in the future is the addition of networked communications that will allow many of these embedded computations to coordinate with each other and with the user. Human interfaces to these embedded devices will in many cases be very different from those appropriate to workstations.

Augmented reality [edit]

A common staple of science fiction, augmented reality refers to the notion of layering relevant information into our vision of the world. Existing projects show real-time statistics to users performing difficult tasks, such as manufacturing. Future work might include augmenting our social interactions by providing additional information about those we converse with.

Factors of change [edit]

Question book-new.svg
 This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (October 2010)

Traditionally, as explained in a journal article discussing user modeling and user-adapted interaction, computer usage was modeled as a human-computer dyad in which the two were connected by a narrow explicit communication channel, such as text-based terminals. Much work has been done to make the interaction between a computing system and a human. However, as stated in the introduction, there is much room for mishaps and failure. Because of this, human-computer interaction shifted focus beyond the inter-face (to respond to observations as articulated by D. Engelbart: "If ease of use was the only valid criterion, people would stick to tricycles and never try bicycles."[11]

The means by which humans interact with computers continues to evolve rapidly. Human–computer interaction is affected by the forces shaping the nature of future computing. These forces include:

  • Decreasing hardware costs leading to larger memory and faster systems
  • Miniaturization of hardware leading to portability
  • Reduction in power requirements leading to portability
  • New display technologies leading to the packaging of computational devices in new forms
  • Specialized hardware leading to new functions
  • Increased development of network communication and distributed computing
  • Increasingly widespread use of computers, especially by people who are outside of the computing profession
  • Increasing innovation in input techniques (e.g., voice, gesture, pen), combined with lowering cost, leading to rapid computerization by people previously left out of the "computer revolution."
  • Wider social concerns leading to improved access to computers by currently disadvantaged groups

The future for HCI, based on current promising research, is expected[12] to include the following characteristics:

  • Ubiquitous communication. Computers are expected to communicate through high speed local networks, nationally over wide-area networks, and portably via infrared, ultrasonic, cellular, and other technologies. Data and computational services will be portably accessible from many if not most locations to which a user travels.
  • High-functionality systems. Systems can have large numbers of functions associated with them. There are so many systems that most users, technical or non-technical, do not have time to learn them in the traditional way (e.g., through thick manuals).
  • Mass availability of computer graphics. Computer graphics capabilities such as image processing, graphics transformations, rendering, and interactive animation are becoming widespread as inexpensive chips become available for inclusion in general workstations and mobile devices.
  • Mixed media. Commercial systems can handle images, voice, sounds, video, text, formatted data. These are exchangeable over communication links among users. The separate worlds of consumer electronics (e.g., stereo sets, VCRs, televisions) and computers are partially merging. Computer and print worlds are expected to cross-assimilate each other.
  • High-bandwidth interaction. The rate at which humans and machines interact is expected to increase substantially due to the changes in speed, computer graphics, new media, and new input/output devices. This can lead to some qualitatively different interfaces, such as virtual reality or computational video.
  • Large and thin displays. New display technologies are finally maturing, enabling very large displays and displays that are thin, lightweight, and low in power consumption. This is having large effects on portability and will likely enable the development of paper-like, pen-based computer interaction systems very different in feel from desktop workstations of the present.
  • Information utilities. Public information utilities (such as home banking and shopping) and specialized industry services (e.g., weather for pilots) are expected to proliferate. The rate of proliferation can accelerate with the introduction of high-bandwidth interaction and the improvement in quality of interfaces.

Academic conferences [edit]

One of the top academic conferences for new research in human-computer interaction, especially within computer science, is the annually held ACM's Conference on Human Factors in Computing Systems, usually referred to by its short name CHI (pronounced kai, or khai). CHI is organized by ACM SIGCHI Special Interest Group on Computer–Human Interaction. CHI is a large, highly competitive conference, with thousands of attendants, and is quite broad in scope.

There are also dozens of other smaller, regional or specialized HCI-related conferences held around the world each year, the most important of which include:[13]

Special purpose [edit]

Footnotes [edit]

  1. ^ Card, Stuart K.; Thomas P. Moran; Allen Newell (July 1980). "The keystroke-level model for user performance time with interactive systems". Communications of the ACM 23 (7): 396–410. doi:10.1145/358886.358895. 
  2. ^ Carlisle, James H. (June 1976). "Evaluating the impact of office automation on top management communication". Proceedings of the June 7–10, 1976, National Computer Conference and Exposition. pp. 611–616. doi:10.1145/1499799.1499885. "Use of 'human-computer interaction' appears in references"  Missing or empty |url= (help); |accessdate= requires |url= (help)
  3. ^ Ergoweb. "What is Cognitive Ergonomics?". Ergoweb.com. Retrieved August 29, 2011. 
  4. ^ "NRC: Backgrounder on the Three Mile Island Accident". Nrc.gov. Retrieved August 29, 2011. 
  5. ^ http://www.threemileisland.org/downloads/188.pdf
  6. ^ Green, Paul (2008). Iterative Design. Lecture presented in Industrial and Operations Engineering 436 (Human Factors in Computer Systems, University of Michigan, Ann Arbor, MI, February 4, 2008.
  7. ^ Kaptelinin, Victor (2012): Activity Theory. In: Soegaard, Mads and Dam, Rikke Friis (eds.). "Encyclopedia of Human-Computer Interaction". The Interaction-Design.org Foundation. Available online at http://www.interaction-design.org/encyclopedia/activity_theory.html
  8. ^ Pattern Language
  9. ^ Wickens, Christopher D., John D. Lee, Yili Liu, and Sallie E. Gordon Becker. An Introduction to Human Factors Engineering. Second ed. Upper Saddle River, NJ: Pearson Prentice Hall, 2004. 185–193.
  10. ^ Brown, C. Marlin. Human-Computer Interface Design Guidelines. Intellect Books, 1998. 2–3.
  11. ^ User Modeling and User-Adapted Interaction 2001, Volume 11, Issue 1-2, pp 65-86
  12. ^ SINHA, Gaurav; SHAHI, Rahul; SHANKAR, Mani. Human Computer Interaction. In: Emerging Trends in Engineering and Technology (ICETET), 2010 3rd International Conference on. IEEE, 2010. p. 1-4.
  13. ^ http://www.confsearch.org/confsearch/faces/pages/topic.jsp?topic=hci&sortMode=1&graphicView=true

Further reading [edit]

See also: List of user interface literature
Academic overviews of the field
Historically important classic[citation needed]
Overviews of history of the field
Academic journals
  • ACM Transactions on Computer-Human Interaction
  • Behaviour & Information Technology [1]
  • EMinds International Journal on Human-Computer Interaction
  • Interacting with Computers
  • International Journal of Human-Computer Interaction
  • International Journal of Human-Computer Studies
  • Human-Computer Interaction [2] [3]
Collection of papers
Treatments by one or few authors, often aimed at a more general audience
Textbooks

External links [edit]

 This article's use of external links may not follow Wikipedia's policies or guidelines. Please improve this article by removing excessive or inappropriate external links, and converting useful links where appropriate into footnote references. (February 2013)
Wikimedia Commons has media related to: Human-computer interaction
Source: http://en.wikipedia.org/wiki/Human%E2%80%93computer_interaction

Continue Reading