Towards a Theory of Diagnosis in Second and Foreign Language Assessment: Insights from Professional Practice Across Diverse Fields

Diagnostic language assessment has received increased research interest in recent years, with particular attention on methods through which diagnostic information can be gleaned from standardized proficiency tests. However, diagnostic procedures in the broader sense have been inadequately theorized to date, with the result that there is still little agreement on precisely what diagnosis in second and foreign language learning actually entails. In order to address this problem, this article investigated how diagnosis is theorized and carried out in a diverse range of professions with a view to finding commonalities that can be applied to the context of language assessment. Ten semi-structured interviews were conducted with professionals from the fields of car mechanics, IT systems support, medicine, psychology and education. Data were then coded, yielding five macro-categories that fit the entire data set: (i) definitions of diagnosis, (ii) means of diagnosis, (iii) key players, (iv) diagnostic procedures, (v) treatment/follow-up. Based on findings within these categories, a set of five tentative principles of diagnostic language assessment is drawn-up, as well as a list of implications for future research.