In this interview Professor Green explains the work of CRELLA (the Centre for Research in English Language Learning and Assessment at the University of Bedfordshire), and its role in the improvement of language testing. The institute contributes to this effort in many ways. For example, in the field of language education they are partners in English Profile (EP: www.englishprofile.org), a collaborative research programme directed towards a graded guide to learner language at different CEFR (Common European Framework of Reference) levels, based on the 50 million word Cambridge Learner Corpus. Among other things, the EP has helped to inform the development of the CEFR-J in Japan. In this interview, Professor Green also outlines his own work, especially in the areas of washback and assessment literacy.