I think using already made videos can be a valuable resource and intend on using them in my classroom as long as I can find some that really drive home the point of the lesson or can help to facilitate learning of a lesson effectively. I do not think they are necessary for every lesson but do think for some lessons they can really help students to grasp some material. I would also like to allow students to create their own videos as a cap stone project to show how they bring all the material together into one final culminating point. There are resources available to teachers to help them integrate video production as a project. Below are some examples of ways that videos can be used in todays 21st century classroom.
Video Credit: Kristyna Maree via youtube
Video Credit: Cisco via youtube
