you do realize graduate and undergrad students do research in labs as part of thier degree, or lab experience right. they are indeed researchers, just not labeled as such by employers to pay them a wage or any benefits. and also they do most of the lab work as well, the postdocs/PI are the ones drumming up the IDEA, and implementing some of the experiments. if you go to any research paper from a science journal you can sometime see graduate and undergraduate researcher as part of the affliate"acknowlegement of the paper.