This document provides an overview of qualitative research methods. It discusses various qualitative research designs including case studies, comparative studies, retrospective studies, and longitudinal qualitative studies. It also covers qualitative research sampling techniques like theoretical sampling and purposive sampling. Common qualitative study designs such as ethnography, phenomenology, grounded theory, and participatory action research are defined. The document also discusses principles of qualitative research including saturation, appropriateness of the approach, and fitting the approach into the research process.