The Search for Reliable Generalizations About Messages A Comparison of Research Strategies

Two ways of conducting the search for generalizations about messages are considered: Morley's (this volume) proposal that single‐message research designs be used, with subsequent meta‐analytic summaries, and Jackson and Jacobs's (1983) proposal that multiple‐message designs be used, with messages treated as a random factor in the statistical analysis. Jackson and Jacobs's approach is shown to provide a more dependable, efficient, and practical means for gathering the requisite evidence for dependable generalizations. The charge that multiple‐message designs suffer from irreparable problems of experimenter bias is refuted. The treatment of messages as a random factor is defended as statistically appropriate and as clearly preferable to the statistical alternatives.