<p>are you just assigned to one?</p>
<p>You pick your discussion section and the GSI that you get is the one that is assigned to lead that section. You don’t know which GSI is assigned to which section beforehand, though.</p>
<p>Although you pick a discussion and a GSI is assigned to a discussion, you can certainly “pick” a GSI in certain cases. For example, you can go to different discussions during the first week for a class and pick the GSI you like best. But this really only works if the class is not even near full enrollment.</p>