APA Dictionary of Psychology

a strategy, often adopted in qualitative research, that involves the purposive sampling of further data while a theoretical framework is still under construction. To gain a deeper understanding of the constructs involved, the researcher samples new research sites, cases, incidents, time periods, or data sources to compare with those that have already been studied. In this way, they seek to build a theory from the emerging data while continuing to select new samples to examine and elaborate on the theory. See grounded theory.