Distinguishing the Trees from the Forest: Applying Cluster Analysis to Thematic Qualitative Data

Qualitative data analysis requires organizing and synthesizing often large quantities of text. In many cases, this analysis entails negotiating the interplay between raw data, semantic themes or codes, and the overarching conceptual framework. In this article, the authors use a case study, which examines HIV vaccine efficacy trial participants' discourse, to demonstrate how cluster analysis can be used to aid in the analysis of large qualitative data sets. After briefly reviewing the systematic approaches to qualitative analysis and describing the project background, the authors present an example of how a hierarchical cluster technique can be incorporated into a multistage thematic analysis.