Presented is an analysis of science instructional techniques using different media (printed material and/or audio tapes) in learning and testing modes. Three hypothetical concepts in biology and a retention test for each were developed. Three hundred fifty tenth-grade biology students were randomly assigned to nine subgroups which were identifiable by the unique combination of programed text format group-paced delivery techniques utilized for each in the learning and subsequent testing sessions. Analysis of covariance indicated that there was no advantage either in presenting the verbal information using a combination of audio and printed media simultaneously nor in using the same media in the learning and testing sessions. (Author/EB)