Before starting with git, let’s identify a few workflows that scientists actually use, then try and map git onto them. Hopefully, these are workflows that people already use.
1. The lone scientist
This workflow will seem very familiar to anyone working on a project where they are the main contributor, especially PhD students. You do some work, and then you save the contents of your directory. It looks like:
- Do work
- goto 1
2. Computer synchronisation
This is probably familar to anyone who has two computers.
I have a desktop for doing computing that requires grunt, and a laptop for cafe work or travel, and I need to keep my projects synchronised. Dropbox largely solves this problem when you don’t care about version control, and some people will use it with the workflow above (be careful though as this can lead to corruption in your git repository – e.g., see this thread on stack overflow).
In this workflow, you will usually work on computer A, “push” all your changes to a server (say, bitbucket or github), then “pull” changes down to computer B, work on that, and push the changes up onto the server (rinse and repeat). Notice that there is a third computer involved here.
This workflow works great, until you do work on both computers in which case you’ll find yourself doing “Synchronous collaboration” (below) with yourself.
3. Asynchronous collaboration
This is essentially the model that you do when you do track changes with your supervisor. In this workflow, you do some work, then your collaborator does some work. You then review their work and apply it to yours.
A bit of mental gymnastics reveals that this is actually exactly the same as the workflow above (computer sync). But now computer B happens to be owned by somebody else, and you don’t always accept all their changes.
It also becomes clear that you could possibly both edit the files at the same time, or that you might have more than one “other” person, in which case you are again doing “Synchronous collaboration”.
4. Synchronous collaboration
In this case here, you have multiple people working on the files at the same time. Different people may make changes to different files at the same time. It quickly becomes desirable to denote a “canonical” copy.
Most software projects in the world operate in this way, but this is not actually that common for ecologists. This is the jumping off point for most dicussions on using version control, but we’ll leave it until later, if we get time to cover it.