Secondly, let us look at diagnostic tests. This test, sometimes called the formative or progress test, checks on student's progress in learning particular elements of the course. It is used, for example, at the end of a unit in the course book or after a lesson designed to teach one particular point. These tests can take the form of an extension of the lesson from a practice phase into an assessment phase. They can provide information about progress which may be used systematically for remedial work. The diagnostic test tries to answer the question "How well have the students learned this particular material?" If his learning has been successful, the results will give a considerable lift to the student's morale and he is likely to approach the next learning tasks with fresh enthusiasm. If he finds he has not mastered the point at issue, the test should give him clear indication of how he falls short, so that he can do some useful revision. Next, achievement test. An achievement test, also called an attainment test, looks back over a longer period of learning than the diagnostic test, for example, a year's work, or a whole course, or even a variety of different courses. It is intended to show the standard which the students have now reached in relation to other students at the same stage. This standard may be established for a country, as with school-leaving certificates; or it may relate to an individual school or group of schools which issues certificates to students attending courses. But the important point which is common to all these situations is that the standard remains constant as far as possible from course to course and from year to year and is external to the individual class or textbook.