“…There is thus a painful absence of a model which might set tangible standards as well a clear concept of how a well-done experiment progresses (Conway, Mendoza & Read, 1963). -The supervision of laboratory work is often inadequate, 9 assessed work is not marked and returned within a period of time so as to have an effect on learning, 9 assessment (and penalization) is often arbitrary and has little teaching value, 9 constructive feedback is often lacking (Reif & St. John, 1979;Court, Donald & Fry, 1976;Fowler, 1969). …”