This volume contains a selection of research papers that were presented at the 15th Annual Language Testing Research Colloquium (LTRC) on the themes of performance testing, and on aspects of communication in relation to cognition and assessment. This edited collection includes contributions reporting research into the testing of speaking and writing, especially in relation to raters, tasks and assessment criteria, contributions exploring the application of various statistical methods in langauge test validation and contributions addressing the issues relating to langauge testing in specific contexts with particular candidate groups. This volume will be of relevance to language testing specialists concerned with the design, development, delivery and validation of performance tests, as well as to academic researchers and graduate students interested in the complex relationship between cognition and assessment.