McCay-Peet, L., & Quan-Haase, A. (2017). What is social media and what questions can social media research help us answer? In L. Sloan & A. Quan-Haase (Eds.), The SAGE handbook of social media research methods (pp. 13–26). London: Sage. SAGE Research Methods doi:10.4135/9781473983847.n2

These authors review the multiple definitions and types of social media that can become research data and identify the kinds of questions that can be answered with social media data.

See also Chapter 14/15: Conlon et al. (2020) on theoretical sampling.

Maxwell, J. A. (2008). Designing a qualitative study. In L. Bickman & D. J. Rog (Eds.), The SAGE handbook of applied social research methods (Vol. 2, pp. 214–253). Thousand Oaks, CA: Sage.

Joseph Maxwell presents qualitative design as involving five key components that together form an interactive system. He suggests a range of strategies and tools to assist in creating a cohesive design and in developing a research proposal from that design.