Volume 38 - Number 3 - 1997 | DOI: 10.5032/jae.1997.03001
A set of instructional materials on Total Quality Management livestock practices was evaluated by preposttest measures of attitudes. The posttest was administered one year after the pretest, and students were paired on three measures, gender, grade in school, and whether or not they raised livestock. Contrary to researchers' expectations, attitudes after use of the materials tended to be lower than attitudes before use of the materials. But when ratings on the posttest were compared with a control group of students, there were significant differences favoring those taught with the new materials. Females rated their use of TQM livestock practices higher than males as did those with livestock compared with those without. Also, the 10th and 11th graders had higher ratings than 12th graders. This study illustrated some of the difficulites in evaluating instructional materials without disrupting the flow of classes. Historical factors and differential selection are two of the extraneous variables cited as affecting this pre-post study. Recommendations for future evaluations of instructional materials are to use a variety of methods to assess their value.