Q-sort: a tool that is occasionally used in therapy. A pack of cards containing statements are presented to the client, who then sorts these into a number of categories (for example, 'very like me', 'not at all like me' and so on). If therapy is successful, there will be a shift from a great distribution of negative cards to positive cards, to reflect a positive self-image.

qualitative research (data): information in nonnumerical form, e.g. speech, written words, pictures, which places importance on the meaningful interpretation of data, rather than simply converting data to numbers, for instance, material gathered from a case study.

quantitative research (data): information in numerical form, e.g. number of students in a class, average scores on a quiz.

quasi-experiment: an experimental design whereby the experimenter does not directly influence participant allocation to different conditions, but instead utilises existing groupings.

questionnaire (survey): a research method that is contains different formats of questionnaires, for example the Likert scale, open- and closed- questions.

quota sampling: a technique for obtaining participants by selecting a quota of individuals, in proportion to their frequency in the population.