Question

According to the manual we should wath only the lecture video clips, isn't it necessary to watch the whole video or what?

Answer 1

They have been hand picked as the necessary or important parts. It means you don't have to watch less interesting or relevant parts, and in some cases sections are rearranged to follow the logical progression of the material. It also means you can get basically as much out of watching maybe 15-20 minutes instead of 50. If your afraid you may miss something you can just watch the entire thing

Answer 2

sometimes I watch the whole lecture if I need to see that section in its entirity :)
but the bits are ok to watch.. they serve the same purpose :)