There are many reasons why instructors like to break away from lecture or presentation mode to show a video. A video can add a visual element to your content and address different learning styles. It can help break up your content. Adult learners prefer to see how content is applied in a real world situation and videos can sometimes provide that better than a presentation slide for lecture. However, a video in a class (online or F2F), needs to be treated instructionally. It’s the content in the video that is important. Instructions shouldn’t just say (or write on your course page), “watch this video.”
Do students know why they are watching it? Have you communicated an objective?
After students watch the video, then what? Following the video, there should be a connection to your course content. What is the activity, discussion or assignment that will follow? Don’t just show or post a video and leave it at that. If the lesson includes multiple media selections, your assignments and activities should include and reference them also. You wouldn’t assign a reading and then never address it again. Your video selection shouldn’t be treated differently.