Interest in assessment that supports learning has grown, partly because of its potential for improving learning (e.g. Black & Wiliam 1998). However, there is considerable variation in what such assessments are called (e.g. diagnostic, formative, assessment for learning), what their theoretical basis is, and how they are implemented in practice. This presentation focuses on the diagnostic assessment of second / foreign (L2) language skills, which has become a lively area of research and development in the broader field of language assessment.

First, Huhta will discuss similarities and differences between diagnostic tests / assessments (DiagA) and other types or purposes of assessment such as proficiency and placement testing as well as other formative types of assessment. The main part of his talk gives an account of the emergence of DiagA in L2 as field of study, its key developments and current state. He will also offer some thoughts about how the field is likely to evolve in the future and the research that is needed.

Huhta will illustrate the developments in DiagA by describing three projects which also exemplify both the challenges and solutions in this field. Some of the ways to address the challenges involve the use of technologies (nowadays artificial intelligence, too), others rely on progress in conceptualizing DiagA. The first key project is DIALANG, which began systematic work on DiagA in the late 1990s, but which also pioneered other important developments in L2 assessment such as operationalizing the Common European Framework and aligning test results with it (e.g. Alderson 2005). The second project is Dialuki (2010-2013/15), a study that investigated how L2 reading and writing skills can be predicted with a range of linguistic, psycholinguistic, motivational and background factors (e.g. Alderson et al. 2015). The third project, DD-LANG, exemplifies a promising avenue for L2 DiagA that combines it with dynamic assessment, which can expand the scope of diagnosed skills (e.g. Leontjev, Poehner & Huhta 2025).

Ari Huhta is professor of language assessment at the Centre for Applied Language Studies, University of Jyväskylä, Finland. He has investigated diagnostic foreign/second language assessment, computerised assessment, self-assessment, as well as the development of reading, writing and vocabulary skills. He was involved in developing the multilingual DIALANG online assessment and feedback system in the early 2000s. He has co-authored two books on diagnosing L2 reading (2015) and writing (2024). He currently leads two projects: one on English as a foreign language and another on Finnish as a second language that both combine dynamic and diagnostic assessment and use artificial intelligence.