External validity and the use of real people as subjects.

The Appropriateness of Using Laboratories and Student Participants in Gambling Research

“…In a 1977 editorial for the Journal of Consumer Research, Robert Ferber argued against the use of convenience samples (usually university students) for two reasons; firstly, the participants may be inappropriate if they are not consumers of the product being investigated, and second, because the sample is not based on any formal plan that would allow the results to be generalised to a larger population. In contrast Oakes (1972) investigated the external validity of using university student subjects as compared to nonstudent subjects and concluded that while there were limitations to the external validity of using college students (the "science of sophomores" (Oakes, 1972, p. 962)), there were as many limitations to the external validity of using 'real people' and, therefore, research with college students as subjects is just as valid as research drawing on any other subject population. Furthermore, Oakes (1972) argued that any behavioural phenomenon found in a certain population, may not exist among members of another population, but this does not make it any less genuine, and it would be true no matter what population one sampled in the original research.…”

Methodological variables in Web-based research that may affect results: Sample type, monetary incentives, and personal information

“…Several authors have commented on the potential problems involved in using undergraduate students as a sample of the general population (e.g., Oakes, 1972;Sears, 1986). Undergraduates required to participate for course credit may differ in motivation from self-selected adult volunteers.…”

Web-based research: Methodological variables’ effects on dropout and sample characteristics

“…There are obvious demographic and attitudinal differences between undergraduates and nonstudents (Oakes, 1972;Sears, 1986). Research has not addressed whether similar differences arise as a result of different methods of recruiting nonstudents.…”