Say you want to conduct a research study that observes people engaged in a generic activity. Rather than record this evidence oneself, would it be wise to try to gather recorded evidence that was part of other research studies? I am asking about gathering raw evidence, to re-analyze for the purposes of a new study, not leveraging/citing data/conclusions in other research studies. For example, if another research study recorded 1000 hours of people doing general enough activities, would I be able to ask the owner of that study to share their recorded evidence with me, so that I might use it for my own analysis?
In other words, what are some of the issues to consider when using secondary data?
If it isn't common, why not? What are the pitfalls of using evidence gathered from other studies, to drive my own research?