GERO 300 Lecture Notes - Lecture 8: Nonprobability Sampling, User Friendly, Longitudinal Study

• School: Simon Fraser University
• Department: Gerontology
• Course: GERO 300
• Professor: Atiya Mahmood

Document Summary

2. describe the characteristics of volunteer research participants: day-to-day physical activity levels were above. A single-blind study is one in which the participant, but not the experimenter, is blind to the condition. Experiments and cross-sectional studies such as surveys are very different with respect to participant recruitment. This stems from their different research purposes and the subsequent demand placed in participants: The major concern of experiments is ensuring internal validity (there is no other explanation for the effect than the intervention). Whereas the main concern in cross-sectional studies, especially surveys, is external validity or generalizability (the findings from a sample represent what would be found in the entire population). These two designs require vastly different levels of commitment from participants: Participation in an experiment takes a considerable amount of time and energy, may involve physical and/or psychological risks, and often requires getting to where the intervention and measurement equipment are located, perhaps multiple times over the course of months.