This document discusses qualitative research methods for systematically collecting data. It describes various non-probability sampling techniques like convenience sampling, purposive sampling, quota sampling, and snowball sampling. Sample size in qualitative research typically continues until information redundancy or saturation occurs, with rules of thumb based on the research approach, data collection method, and length of interviews. Qualitative data collection methods are time-consuming so samples are usually smaller, but the information is richer with deeper insight into the phenomenon studied. Data analysis involves examining, categorizing, and recombining evidence to address the study's initial propositions.