volunteering for a study (exam question)

[Spreadbury]

does it seem weird to anyone else that if a study relies on volunteers from the population of research interest that the results are unrepresentative of the population?

read the VCAA 2008 research methods experiment section, and the answers to questions 15 and 21. I got those wrong, and it just kind of surprises me. volunteers do not seem like it discriminates if they're all offered a chance to participate. after all, relying on volunteers means you're relying on voluntary participation (although in that research experiment, it wasn't entirely voluntary- read it and you'll find out. confusing otherwise haha!

[masonnnn]

does seem weird but it makes sense.
imagine the population was your whole school cohort,
needs to represent ALL members, roiiiiight?
but there'd be a bias because of a lot of reasons.
ie. those students who couldn't give less of a @#%^& about school, would not volunteer, yet they're part of the population so it's unrepresentative.
and some others who may have volunteered won't because imagine, they didn't see the advertisement or walk near where the advertisement was.

it's pretty cheeky really.
aha

[Glockmeister]

As an aside, if you do first-year psychology, one of the requirements for coursework is that you must either participate in a scientific study or complete an exercise about research ethics. Consequently, university students tend to be rather popular with psychology researchers, even if it might be quite inappropriate.