Interactive videos keep the viewer engaged, help highlight critical points and can assess the viewer’s knowledge. The annotation and spotlight options within YouTube can be used to link a series of videos you have created. [youtube]http://www.youtube.com/watch?v=C5zzVemi3m4[/youtube] Read more about YouTube annotations: https://support.google.com/youtube/answer/92710?topic=14354&hl=en There are also services designed to create video-based quizzes. Blubbr is a free…