THIS RESEARCH INVOLVED THE SELECTION OF TWO EXTANT TEACHING FILMS, DEVELOPMENT OF TESTS ON THEIR CONTENT, REVISION OF THE FILMS, AND A COMPARISON OF THE TWO VERSIONS. THE FILMS SELECTED WERE "WHY FOODS SPOIL" AND "ATOMS AND MOLECULES." THE SUBJECTS CONSISTED OF STUDENTS IN SMALL TOWN SCHOOLS FROM 5TH TO 12TH GRADES. MULTIPLE-CHOICE TEST ITEMS WERE CONSTRUCTED AND ADMINISTERED TO REPRESENTATIVE GROUPS OF STUDENTS WHO HAD SEEN THE APPROPRIATE FILMS. DATA WERE USED TO IMPROVE THE ORIGINAL FILMS. THE REVISED VERSIONS WERE PRESENTED TO ONE-HALF OF EACH GROUP. TESTING SESSIONS WERE HELD TO COMPARE THE ORIGINAL AND REVISED VERSIONS. THE DATA WERE ANALYZED TO COMPARE MEAN SCORES BETWEEN VERSIONS AND TO COMPARE PROPORTIONS SELECTING VARIOUS ALTERNATIVES IN EACH MULTIPLE-CHOICE ITEM. THE MEAN SCORES INDICATED THAT THE REVISIONS IMPROVED THE EFFECTIVENSS OF THE FILM, BUT SOME OF THE TEST ITEMS WERE FOUND TO HAVE NO RELEVANCE TO THE REVISIONS. (RS)