In this activity, lectures were indexed by topic and posted online so that students could re-watch segments on specific topics. In Math 23b, Professor Paul Bamberg offered students extra credit for indexing lecture. They would create a document giving the time breakdowns for each topic. This would then be posted on isites as a guide to the already-posted lecture video. Not only did this encourage students to re-watch lectures, but it led to the creation of a valuable resource that other students could draw on.

Here is an example from the first lecture.

**Math 23b/Math E-23b**

**Tuesday, January 24**

**Index: Lecture 1**

00:00 Introduction

CA information

Course administrative business

10:00 Page 2: Extending integrals to more than one dimension

22:13 Page 3: The overall plan of attack

27:03 Page 4: Some useful definitions

30:15 Page 4: Revisiting Riemann integrals in one dimension

41:30 Page 6: Generalizing to n dimensions

46:37 Page 6: Limitations

52:53 Page 7: Some theorems

55:34 Page 8: Proof 12.1 -- start to finish

72:50 Page 9: A useful product rule: Proposition 4.1.16