A computerized text and cluster analysis approach to psychotherapy talk across time

This paper illustrates an analytical approach combining LIWC, a computer text-analytic application, with cluster analysis techniques to explore 'language styles' in psychotherapy across sessions in time. It categorizes session transcripts into distinct clusters or styles based on linguistic (di)similarity and relates them to sessional progression, thus providing entry points for further qualitative exploration. In the first step, transcripts of four illustrative therapist-client dyads were scored under ten LIWC variables including 'analytic thinking', 'clout', 'authenticity', 'emotional tone', and pronoun types. In the next step, agglomerative hierarchical clustering uncovered distinct session clusters that are differently distributed in each dyad. The relationships between these clusters and the chronological progression of sessions were then further discussed in context as contrastive exemplars. Applications, limitations and future directions are highlighted.