In 1973, Harriet Williams published in "Quest" on volunteer bias (self-selection bias) in kinesiology research. Williams' evidence-based commentary included a discussion on sex differences in volunteerism. More recently, some exercise and sports scientists (ESS) have suggested "investigator" bias explains the lower proportion…

Imagery research with children has been primarily examined within a structured physical activity context. However, researchers have begun to investigate children's imagery use in their active play (i.e., unstructured leisure-time physical activity). The objective of the present article was to develop a conceptual model of active play imagery--the…