Presented at the annual meeting of the National Association for Research in Science Teaching (NARST) in April, 1972, in Chicago, this study compared the achievement and retention of ninth grade physical science classes receiving instruction with a prior knowledge of behavioral objectives with ninth grade classes taught the same material without prior knowledge of the objectives. The resultant data indicated that classes with a prior knowledge of the objectives did achieve significantly higher on the achievement test and retention test employed. (Author/CP)