Reported is a study designed to test Hovland's principle of attitude change as related to attitudes toward science and science teaching. Hovland's research provided information that communicators who were perceived as being highly credible and authoritative are more likely to produce greater attitude change than are communicators perceived as less credible and authoritative. A one-group pretest-posttest-posttest test time series research design was used with 25 preservice elementary education students enrolled in a science methods course. Treatment consisted of: (1) on-campus methods instruction and science unit planning during weeks 1-7 of one quarter; (2) in-field preservice elementary teacher science instruction of pupils in local elementary schools during weeks 8-10; and (3) an on-campus science fair and evaluative feedback sessions during the final week of the quarter. Preservice students' attitudes toward elementary science teaching and toward science were measured with Moore's Science Teaching Attitude Scales instrument while perceptions of communicator credibility were measured by the semantic differential technique in the form of the Perceptions of Communicator Attitudes instrument. The investigator concluded, after data analysis, that Hovland's principle is important to attitude change but that credibility is not the main cause for change. (PB)