Table 1.

Key features of longitudinal qualitative research and approaches to qualitative research

	Longitudinal qualitative research	Ethnography [15]	Participatory action research [16]	Biography [17]
Focus of study	Exploring temporal dimension of a phenomenon in individuals and in groups	Describing and interpreting a cultural or social group	Seeking collaborative change by actively engaging participants	Exploring the life of an individual
Type of data	Cross sectional and longitudinal data, typically collected via interviews with a relatively small group of individuals	Typically prolonged observation of, and ad hoc field interviews with, members of cultural or social group	Typically cross sectional data collected from multiple individuals	Longitudinal data collected via interviews and/or existing documents and archives
Nature of research relationship	Increasingly personal due to time, repetition, and familiarity	Determined by the stance of the researcher (detached observer to complete participant)	Empowering and collaborative	Singular; Varies from close/personal to more detached