Audio comments may work best for assignments where students have some motivation to listen to the comments, such as assignments where comments must be applied to revisions.  Another strategy is to state the assignment grade at the end of the comments.

Students will get the most out of the commentary if you invite them to go through the assignment with you as they watch the recording so that you are “literally on the same page.”

A recorded message for students needn’t be long.  You may only want to point out two or three things that are best expressed aloud, such as praising a skillfully balanced sentence, or deconstructing a problematic argument.  

Students often benefit from hearing what they did successfully as well as what could be improved.  Beginning by identifying aspects in which the student’s work is strongest before diving into constructive criticism can also help open the student to your suggestions. 

It’s helpful to consider students’ technological resources and abilities.  In some cases, giving students the option to have written comments may be appropriate.  Some students may need some instruction about how to access comments.  

Students also will benefit from instructions about how they should absorb comments.  Consider having them do a five-minute free-write about their reactions to your comments.  You also could request they write their own questions and comments in the margins of their papers as they listen. 

Many instructors and students prefer to give students a copy marked only for mechanical mistakes in addition to the recorded comments.