An Experimental Evaluation of the Relative Effectiveness of Certain Audio-Visual Aids in Vocational Agriculture
The selection of the cooperating schools.--The schools which cooperated in this study were selected with the aid of the Agricultural Educa tion staff of the University of Minnesota and the Minnesota State Department of Agricultural Ed ucation. The cooperating schools were located in the southern half of Minnesota and were selected on the basis of the following criteria: (1) the agricultural area in which the school was located; (2) the ability and success of the local teacher of agriculture and his interest and will ingness to cooperate in the proposed experi mental study; (3) the number of students en rolled in the agriculture classes of each school; and (4) the cooperation which might be expected from the administrators in each school.