Written Corrective Feedback

As teachers, grading and providing feedback is one of the most important (and time consuming) parts of our job. I think it's essential that we think about how we provide feeback and purporse of that feedback. How can we best help students learn through our comments? How can we make these comments time effecive, especially when we have many students in only one class?

I recently came across a great presentation given by Dr. Rod Ellis on written corrective feedback on YouTube. He presents about different types of written corrective feedback and their effectiveness. Take a look because I think it's very clear, helpful, and practical.

Here is a shortened version of the video:

One of my colleagues often gives feedback for spoken presentations via the Voice E-mail function on Blackboard. It's basicially a long voice mail providing feedback that otherwise would have been written. He then gives the grade at the end of the e-mail in order to encourage to focus on feedback rather than the grade. I have tried this before, and I like it, but it never seemed to stick... I always go back to pen and paper feedback. Have any of you tried doing this?

How do you provide feedback? Why?