In this article we review studies of situations and situation taxonomies from the perspective of trait psychology. Objections to trait psychology are discussed and several refutations are recapitulated. The relation between traits and situations is analysed, as well as the anity that both concepts demonstrate. Some taxonomic properties are discussed, exempli®ed by one of the most common and detailed trait taxonomies to date, the Abridged Big Five Circumplex, and by seven situation taxonomies. Personality psychologists, besides trait psychologists, have stressed the need to no longer debate the existence of traits, but to specify their nature with increasing precision in dierent situations. What is needed is a taxonomy of personality characteristics that systematically incorporates situational information, so that traits can be questioned in their context, that is, in a context that allows for individual dierences in the expression of trait-relevant behaviour.

A taxonomy of situations was constructed that categorizes situations by means of ratings of one's ability to deal with those situations. A principal components analysis of self-and other-ratings yielded four components of situations: I, situations of pleasure; II, situations of individual adversity; III, situations of interpersonal conflict; and IV, situations of social demand. Ratings of being able to deal with a situation were related to ratings on a personality questionnaire. This resulted in a very clear set of situations for each of the Big Five factors of personality. The Big Five differed in kind and in number of situations for which they were able to distinguish the well handling from the less well handling persons. Especially, it turned out that the so-called temperament-factors, Extraversion, Emotional Stability, and also Autonomy, give rise to more situational differentiation than the socalled character-factors, Agreeableness and Conscientiousness. Comparing the present situation structure to that obtained in an earlier study, we found that using the same set of situations does not guarantee obtaining the same set of situation components. Different methods of classification yield differences in the resulting classifications.were defined in terms of objective situational characteristics, or attributes. The classification of the situation concepts according to these attributes has resulted in a situation taxonomy that consists of ten dimensions: (1) interpersonal conflict; (2) joint working, and the exchange of thoughts, ideals, and knowledge; (3) intimacy and interpersonal relations; (4) recreation; (5) travelling; (6) rituals; (7) sport; (8) excesses; (9) serving; and (10) trading. Until now, Van Heck's taxonomy of situations has been most useful one, because it was constructed on empirical grounds and, moreover, it comprises a broad situational domain. However, it does not include information about individual differences, indispensable from a trait psychologist's point of view.Ten Berge and De Raad (2001) constructed another item pool of situations in the spirit of the psycholexical approach, however using a different methodology. Instead of searching the dictionary for situations, they asked participants to describe situations in which people had shown a particular personality characteristic, yielding a collection of situations that are useful to observe individual differences. Unlike Van Heck (1984), Ten Berge and De Raad (2001) focused explicitly on the 'personality domain of situations', by collecting the situations that had shown to be fit for the expression of trait-relevant behaviour. This resulted in an initial situation pool of 2234 situations that was reduced to a final set of 237 situations.The 'collection' phase that is part of the developing process of a situation taxonomy is usually followed by a 'categorization' phase of the result of this collection. The categorization of situations has been performed through various methods, such as ratings of similarity of attributes of situations (c...