I find that correcting online essays tends to be quite cumbersome and never as easy as regular paper corrections. But I still prefer to have my students write on Google Docs, so I now correct their documents as I read them (as if it were my own document), not using any special markup, and I show students how to use Revision History to see what changes I made to their documents, and thus see their corrections.
Here are the steps the students have to follow:
1. Go To FILE menu, click SEE REVISION HISTORY
2. A column will appear on your right. At the bottom, there will be two options. Make sure SHOW CHANGES box is ticked and toggle the bottom underneath so it says SHOW LESS DETAILED REVISIONS.
3. On the top of the REVISION HISTORY column, you will see the original version and my version, as in this picture.
4. By default, it will show the latest changes (in this case, my corrections done on Feb 11). – I have added the red squares for clarification. The changes are marked with a different color font.
5. You can ask students to write their mistakes in a log or list (I do this when I teach Advanced Composition and Grammar) or you can just tell them to look for the corrections and make a mental note.
Revision History is also useful when students are working with other peers, to see who wrote what, and to “correct” any blunders anybody may do inadvertently, as you can restore any older version of a document.
Of course, I also use INSERT COMMENT to add my own comments, but for little grammatical mistakes, like agreement or preposition use, I find this method much quicker.
Let me know how you use this feature and thanks for reading!