What ‘works’ when retracing sample members in a qualitative longitudinal study?

Abstract

Attrition represents a significant obstacle to overcome in any longitudinal research project. It is, perhaps, most keenly felt when the data collected are from a qualitative study, since, unlike quantitative longitudinal research, weighting factors cannot be applied to ‘correct’ for any biases in the achieved sample and even a small number of ‘lost’ respondents can equate to a large percentage of the original sample. It is perhaps because of qualitative longitudinal research’s (QLR) reliance on, generally speaking, smaller samples that few have been able to shed much light on which re-contacting procedures are associated with achieving higher rates of retention. In this article, using data from a fifth sweep of a larger but particularly challenging cohort of 199 former probationers, we explore the strategies which helped us maintain high levels of retention in a QLR study. The article contains many practical suggestions which others planning or undertaking similar studies may find useful.