This publication contains a selection of research papers presented at the 15th Annual Language Testing Research Colloquium (LTRC). The Colloquium was jointly hosted by the University of Cambridge Local Examinations Syndicate (UCLES) in Cambridge and CITO in Arnhem in the Netherlands. At the Cambridge venue, the papers were presented on the theme of performance testing and at Arnhem, they covered aspects of communication in relation to cognition and assessment. A selection of papers has been made in order to achieve a balanced coverage of these themes. In particular, the research presented includes work on speaking and writing tests where the focus is on raters and tasks; the application of various statistical methods in language test validation; and issues related to language testing in specific contexts and with particular candidate groups.