The work in second language education of the Assessment of Performance Unit, established by the Department of Education and Science of England and Wales to monitor certain areas of the public education curriculum is described. The focus is on the development of a rationale for testing, the elicitation procedures used in the assessment of speaking and writing, methods of assessing performance and their reliability, and the application of the results. Examples of tasks used in the productive language tests and some scales used to measure performance are appended. The methods were developed for testing second language students at the age of 13. (MSE)