COM CM 321 Lecture Notes - Lecture 1: Demand Characteristics, Internal Validity, World War I

• School: Boston University
• Department: Mass Communication, Advertising & Public Relations
• Course: COM CM 321
• Professor: Yiyan Zhang

Document Summary

Advertisers in 50s and 60s discovered that research could be used to persuade. Increasing interest in the effects of media on the public (e. g. children) Increased desire to evaluate advertising and pr campaigns. Research phases in mass media: the medium itself, users and users of the medium, effects of the medium, how the medium can be improved. Research procedures: select a problem, review previous research and theory, develop hypotheses or research questions, determine research design, collect data, analyze and interpret the results, present the results in an appropriate form, replicate the study (when necessary) Internal validity: making sure your research design is measuring what you want to measure, avoid confusing variables and illegitimate correlations, history effect. Instrumentation decay: experimental mortality, sample selection, demand characteristics, experimenter bias, etc. External validity: making sure the research is generalizable, how to improve, use random samples, use representative samples (e. g. age and gender, use heterogenous sample, repeat the study.