This written version of a plenary to the Language Testing Research Colloquium relates research into second language speaking task performance to language testing. A brief review of models of communicative competence and of speaking is provided. Then, two major areas within testing are discussed: the concepts of difficulty and ability for use. The next section covers research into spoken task-based performance, covering effects from task conditions, and from task characteristics. In addition, the measurement of such performance is described and briefly compared with performance rating in testing. Then, the final section relates the task research findings to language testing. A framework for testing spoken performance is outlined, and the general claim made that effective sampling through tests, in order to generalise to real-world performance, can usefully draw on findings from second language task research, as well as the distinction between Conceptualiser and Formulator processes.