Let me give this a try. For the most part, archaeologists dig and study trash, the things discarded and left behind by people. For that matter,so do crime scene investigators. The methodologies and techniques of these two groups are surprisingly similar.

It is no surprise to me that looking at the material in a second hand store would reveal a lot about the community and their choices and preferences.

Like any investigative technique, analysis of trash, either modern or prehistoric, is not infallible. Trash and residue analysis works best when combined with other analytical techniques.