A strength of this approach is there are many mathematical techniques for deriving spaces from data such as multidimensional scaling (Shepard 1962) and latent semantic analysis (Landauer & Dumais 1997).
It is possible to account for people's intuitions or ratings of the similarities between concepts by assuming that judgments of similarity increase with the number of commonalities (weighted by the salience of those commonalities) and decreases with the number of differences (weighted by the salience of the differences).
Structural approaches to similarity (Gentner & Markman 1997) were developed to address limitations of the featural account.
Thus, the relationship between the commonalities of a pair and the differences is important for understanding people's assessments of similarity.
[3] Similarity refers to personality, attitudes, values, interests,[4] and attraction shared between to individuals.
[3] Similarity is closely related to Bryne's social psychology model of interpersonal attraction (1961) which is determined by four variables: propinquity (how our environment and situation play a role in determining how often and to what degree we come in contact), need for affiliation, overt stimulus characteristics (refers to the observable attributes of an individual that serve to elicit positive or negative responses from others), and similarity.
[3][5][6] In short we determine our attraction or liking of another by positive and negative reinforcements and our emotions concerning the matter.
[7] Attitude similarity has also been found to serve as a strong foundation for long lasting friendship.
[3] These findings explain that individuals are more likely to be attracted to those who they perceive to share similar activities with such as occupation and hobbies.
[6] Several explanations have been offered to explain in what way similarity increases interpersonal attraction (like-prefers-like).
For example, two people interested in literature are likely to run into each other in the library and form a relationship (involving the propinquity effect).
[12] Specifically, the 'Big Five' personality trait dimensions (extroversion and introversion, agreeableness and disagreeableness, openness and closeness, conscientiousness and apathetic, as well as mental stability and neuroticism) are behavioural traits often used to assess similarity or dissimilarity in relationships.