This document discusses key concepts of validity in qualitative research. It explains that research design should be reflexive and iterative at all stages. Validity is ensured through techniques like prolonged engagement, thick description, peer debriefing, examining rival explanations, and triangulation of data, theories, methods, and analysts. While qualitative research focuses on depth over breadth, external validity is based on developing theories that can potentially explain other cases rather than statistical generalization. Reliability means using accepted qualitative methods, while confirmability involves researcher reflexivity and maintaining an auditable analysis process. There are no set rules for qualitative research as the appropriate methods depend on the specific research questions, context and phenomena being studied.