<p>I know Cornell doesn't have a shopping period, but do profs mind if we sit in for a little and take a copy of the syllabus? Should you talk to them beforehand so they don't get offended from leaving partway through a lecture?</p>
<p>for large classes, don’t bother. for classes not in your major don’t bother.</p>
<p>however how can you tell whether a class looks promising from 15min of class?</p>
<p>Also, there are ppl who sit in lectures to learn but don’t sign up for credit.</p>
<p>@fallenmerc, eh, you can definitely tell if a class is promising in less than 15 minutes. You can just tell by the way a professor teaches and by the syllabus. </p>
<p>@zvoncek, if your not sure you want to take a certain course, and you have the time to check out the class, I would encourage you to sit in (but sit all the way at the back of the class, close to the door in case you want to leave). For large lectures, it’s okay to get up and leave. Professors won’t be offended since they know it’s the first few days of classes.</p>