Qualitative research focuses on interpreting people's experiences and the world they live in. There are several main types of qualitative research including case studies, grounded theory, phenomenology, ethnography, and historical research. Qualitative data is typically collected through interactive interviews, written descriptions, and observation. Analysis begins during data collection to guide further inquiry. Triangulation involves collecting different types of data from multiple sources to enhance validity. Common challenges include small sample sizes and potential for bias.