Does one typically hand over their research work to their lab if they decide to leave academia? Let's say that I've been part of a research lab at a U.S. university for awhile but do not plan to continue on for my PhD.  What does one typically do with all of their research work, e.g. experimental write-ups, code files and email correspondence with researchers external to the lab?  Does one typically initiate some "handover process" and document all of the work carefully enough so that someone else in the lab gets to inherit the work and take over from that point on, or should one keep their own work theirs, without distributing it to the lab that they were a part of?
Ideally, all work would be carefully documented and discussed with co-workers in the group before someone leaves. Often times, though, departures are much more sloppily handled.

However, the research group obviously retains an interest the lab notebooks, data, and other work products created while someone is part of a research group. For data retention practices, I would say that "best practices" would include leaving the originals with the research group, while the person who created the data keeping a copy for their own personal records later down the line.