Differences in univariate values versus multivariate relationships: Findings from a study of Diana, Princess of Wales

A recent debate has called to light an important issue for communication researchers and other social scientists: Does the use of student samples jeopardize the validity of research? Importantly, this question has failed to make a critical distinction between estimates of univariate values versus those examining multivariate relationships. Estimates of univariate values provide information on the prevalence of an attitude or belief from the sampled population to the overall population. Estimates of multivariate relationships, however, provide information on the validity of our theories. This distinction is examined in a study of identification with Diana, Princess of Wales. Results show that although the estimates of univariate values differed across three samples, the multivariate relationships between the variables were more stable, and therefore the underlying process appears to hold. We argue that this finding illustrates the distinction between estimates of univariate means versus multivariate relationships and is evidence that nonprobability samples can be important for many reasons, including testing the consistency of processes.