Longitudinal Oral History Method

There is no fixed rule, but two to five waves is the most common range in published longitudinal oral history studies. The number should be determined by the temporal arc of the phenomenon: a two-year project studying refugee integration might interview at arrival, six months, and two years (three waves), while a decade-long study of ageing might return annually. More waves produce richer data but require more resources and sustain greater attrition risk.

Attrition is expected and should be addressed in the design. Analytically, participants who complete only some waves still contribute valid data for those waves; their partial longitudinal record should be retained and noted as such in reporting. Methodologically, you should document why participants withdrew where known, assess whether dropouts differ systematically from completers (which could bias findings), and discuss this limitation transparently in the write-up.

No. A quantitative panel study re-surveys the same respondents at multiple time points using structured instruments and aims for statistical generalization. Longitudinal oral history re-interviews the same narrators using open-ended oral history methods and aims for in-depth biographical understanding. The goals, sample sizes, analytic logics, and epistemological commitments are fundamentally different, though both share the longitudinal design principle of following the same participants over time.

Initial consent should cover the entire planned series of interviews and explicitly state the right to withdraw at any time without penalty. At each subsequent wave, it is good practice to re-confirm willingness to continue before the interview begins — a brief verbal or written re-consent. If the project extends unexpectedly or if data use changes, full re-consent is required. Keep records of consent status at each wave and update your ethics protocol if the research scope changes significantly.

A single life-history or biographical interview asks a narrator to look back across their entire life at one moment in time. It captures retrospective accounts but cannot observe how interpretations change. Longitudinal oral history returns to the same narrator after real time has passed, so the researcher can observe both new events and shifts in how the narrator remembers and frames earlier events. The comparison across waves — not any single interview — is the distinctive analytical contribution.