Qualitative research is applied when measurement of certain phenomena in quantitative terms is not possible. It finds much use in social science, psychology and market research. Research into human behavior and motivation rely much on qualitative methods. Qualitative research aims to understand why and how of a phenomenon, as opposed to the what, where and when. Data collection tools for qualitative research includes interviews, observations, documents, reports; some techniques include open ended questions, word association tests, sentence completion tests and story completion tests. The sample size in such research is generally small, and findings pertain to the specific case and generalizations should be carefully made.