If you teach online (or feature an online component alongside your regular F2F course), screencasts can make a colossal difference to the quality and accessibility of your program. It is a pretty common feeling among both students and teachers that online instruction involves a certain element of "blindness" - so alongside your standard video features, screencasts bring "vision" back into the equation in a big way.
I personally prefer easily accessible and fully browser-based screencasting tools, and my two favourites are Screenr and Screenjelly. I'll show you some examples and make some comments about each alongside what I feel are two of the most important considerations I think they cater to for online instruction:
1. The creation of visual tutorials combining text, images and voice
2. Helping students understand, better negotiate their way around (and benefit from) their online program
Let's start with an example from Screenr. This example shows a recent tutorial I added to my online TOEFL Speaking program.
Screenr is great in so many ways. Five minutes is a pretty generous allowance in terms of recording time, and for me has generally been more than enough to make effective tutorials. The recording quality is great, and WILL play on iPhones/iPads as well as your traditional Flash-using devices. You can also adjust and position the actual 'field' of the screencast so as to only show portions of your overall screen rather than the whole kit and kaboodle.
I hope you can see from the example just how convenient a tutorial of this nature is for the students. They can see, read, and listen, and there is the option of full-screen viewing which enhances the experience even more.
Once your screencast is uploaded, Screenr also provides excellent options for distributing your work (with a one-click upload to YouTube, or notification to Twitter), but also for preserving it (you can download it to your computer as a .mp4 file) in a format that allows you to upload it in different applications. This is why I use Screenr for important tutorials meant to last. If, for whatever reason, Screenr vanishes, I can still keep all the great tutorials I've made and upload them through different applications.
And then there's Screenjelly. Instead of a tutorial to fit into a course of study, I want to show you an example of a slightly different application.
In this case, I am responding to a student enquiry, because the student is unsure whether her written work has been checked by me, and if so, where in the blazes she can find it! The regular written instructions and links haven't helped her, and while she is in the minority, she's certainly not an exception. Some students really need to SEE what it is they're supposed to do, and this is where screencasts really flex their muscles!
Screenjelly is inferior to Screenr in many respects (only 3 minutes to record, less impressive recording quality, no capacity to download to your computer or upload to YouTube, and full-screen only with no way to adjust the recording field of vision) but it still suits my purposes for quick correspondence because it is extremely simple to use and uploads a lot faster than Screenr. For quick "help" videos demonstrating where to go or what to do for my students, Screenjelly is usually my first preference.
In all honesty, a 1-3 minute screencast using Screenjelly has been infinitely more effective for student help enquiries, saving me endless back-and-forths via email or live text chatting!
So there are two different browser-based screencasting tools for you to consider, Screenr and Screenjelly, highlighting the potential to create effective visual tutorials and also demonstrations of how to actually use aspects of an online program.
They've made an enormous different to my online programs, and they could be great for yours as well!