Transparencies for overhead projectors developed under the leadership of the Texas Education Agency for regular public school classes were modified for use with deaf students by five teachers in the Texas School for the Deaf and a total of 60 sets of modified and unmodified visuals (5000 visuals) was made. Seven schools for the deaf in widely separated areas of the United States agreed to use both the modified and unmodified visuals on an experimental basis, in comparable classes (60 in all with 514 students), both classes having the same teacher. Student age, intelligence, and level of pretest performance were held constant statistically. Analysis of the pre- and posttest data by a statistician indicated no significant difference in achievement between experimental and control groups. There was, however, a highly significant difference between teachers on the subjects taught: earth science, p=.0008; modern mathematics, p=.00005; algebra, p=.00005; geometry, p=.00005; and world geography, p=.00005. The project identified desirable modifications and some characteristics of high quality overhead transparencies for the deaf, and it was concluded that using a sizeable number of consultants in a cooperative approach to educational research is a successful and efficient method. (Author/SN)