If done properly, I see the screencast as an invaluable tool. Teachers can use it to record discussions or demonstrations for absent kids or for kids to reference later. School based administrators can use it to post PD opportunities and communicate to parents. Kids can use them to communicate to their teachers their understanding of a variety of concepts. Remember that screencasts can be used to show anything on a computer...from we sites and how to use them to showing how to use MS Office products. Jing and Camtasia are great tools for making these casts.
Text vs video casts depend on what you are trying to accomplish. If you are showing how annotations are made in a Word, Paint or .pdf document, then perhaps text is the way to go. However, if you are training a group on how a web application works then video is likely your best bet. As a result, the goal of what is being presented seems to dictate how it is received.
In the final analysis, the author of the screencast needs to understand that certain design constraints ought to be adhered to. These include but are not limited to:
- Making sure that the speaking voice is easily understood
- Be careful of cognitive overload...screencasts ought to choose to one topic or capability and stick to it, developing new casts as needed.
- The screen cast ought to include motion...and not those of highlighting text...click a link that the speaker is referring to
- Make the cast interesting and informative so folks will benefit from it.