All Student Samples Differ: On Participant Selection in Communication Science

摘要

When conducting experiments, researchers in communication science often rely on convenience samples of students. This study provides evidence consistent with a concern that between-participant differences in exposure to communication theories can be a threat to the internal validity of conclusions reached. Using cultivation theory as a context for studying this threat, this study examines the influence of stage in university education and discipline of study on the ability to detect the cultivation hypothesis and participants' responses to questions regularly used in studies of cultivation. We found that university students at different stages of their studies and studying different disciplines differed in their responses to questions pertinent to cultivation and also in their ability to identify the cultivation hypothesis. We discuss the consequences of the use of convenience sampling and strategies that may help reduce these effects.