March 24, 2016
‘See revision history’ is a great Google Drive feature that allows you to track changes made to a document, presentation, spreadsheet or a drawing. As a teacher, you can use this functionality to track students' edits and see everything they have been adding to a given file. It’s also ideal for collaborative writing projects in that you get to see the contributions of your collaborators and track changes they have made. Here is a step by step guide to show you how to use this feature:
1- Open your Google Drive file (whether it’s a document, presentation, spreadsheet or drawing)
2- Click on File and select ‘See revision history
3- A panel will be displayed on the righthand side of your document with timestamps and names of people editing the file. Clicking on any timestamp will show you the changes that person made. Changes appear in the same colour found in front of the person’s name in the panel.
4- If you want to revert to the version where the change was made, you simply click on ‘Restore this revision’.
5- To go back to the actual version of your document, click on the back arrow on top left .
To access detailed revisions of your documents, click on ‘show more detailed revisions’ located in the lower corner of revision history panel.
Source:Docs Editor Help