When they are used in the right context flipped lessons can be a good complement to classroom instruction. Not everyone has the time or skill to make effective instructional videos for their students. In those cases you can take advantage of the millions of hours of instructional videos found on YouTube and other video sharing sites. But don't just have your students watch the videos then come back to your classroom. Have them answer some specific questions that you build into the instructional videos that you find online then share with your students.