I am trying to merge three copies of the same document with little success. Here is the situation...

I have a Word 2003 document that contains the state teaching standards for Science in PA. I sent this document to three different teachers and asked them to highlight the standards that they teach in their classes and e-mail it back to me. Each teacher highlighted in different color. Now I have three separate files of the same document with different color highlighting.

Is there any way for me to merge these documents electronically? The goal is to determine the standards that are not being taught as those would be the standards that were not highlighted by anyone.

I've tried using the Compare and Merge documents tool. This seems to work to merge two documents, but I have been unsuccessful in merging the third.

Anyone have any ideas?