The primary research problem confronting many experimental researchers is finding valid stimulus (instructional) and criterial (testing) materials that operationally fit their hypotheses. Five experimental studies have been completed, and two are in progress, using the Dwyer instructional materials to address the problem of finding valid instructional materials that are typical of classroom learning experiences and can be operationally defined in specific psychological terms. Studies used instructional slide tape programs of three types: (1) line drawings with a colored background; (2) illustrations in color; and (3) realistic photographs in color. All of these can be operationally defined as having an effect on abstraction because of the difference between relevant and irrelevant information contained in each set. The Dwyer criterial materials can be operationally defined in specific information-processing terms also, with the drawing test considered a spatial-learning and list-learning task, the terminology test either a simple or conjunctive concept-learning task, and the comprehension test either a complex or relational concept-learning task. The Dwyer materials have been found effective and valid for use in these research studies. (LMM)