In any field of study, teaching and learning go hand in hand with testing. In foreign language teaching, the testing of skills development has become a specialized area requiring the combined efforts of linguists, psychologists, statisticians, and educators. Teachers must constantly ask: What kind of progress are my students making in this second language course? and How effective are the instruction and the materials used in teaching what is to be learned in this course? Some language courses include series of tests; in other cases teachers must design their own tests. The most important point to keep in mind while designing tests is whether or not the results of the tests help to answer the above questions. Raw scores can be very deceiving without further information as to the difficulty of the test or how the scores of all the students relate to each other. The size of the sample must also be considered. More can be decided about the progress of a student from a number of tests taken throughout a course of instruction than from one or two tests taken at the predetermined intervals. The aim of testing is not to penalize the students. The most useful information tests should be closely connected to the teaching, and should be arranged to take the least possible amount of time. Keeping test files is useful for evaluation and review. (AMM)