“…There is considerable controversy on the validity of students' ratings, i.e. whether they indeed measure teaching effectiveness (Costin, Greenough & Menges, 1971; Rippey, 1975; Rodin, 1975; Prey, 1975; Gessner, 1975). Several authors (Gessner, 1973; Frey, 1973; Doyle, 1975) have claimed that students are at least partially capable of identifying qualities of instruction which increase their knowledge or motivation.…”