Hey, Diane!

If you change the reporting values for your questions, it will not effect any of the previously collected responses, but will effect the responses for all of your new survey takers.
So, in your reports, you will see both the old and the new reporting values.
A neat work around for this would be to run a summary report, and choose the option to show question titles rather than reporting values. You could do this without having to change your reporting values or having it effect your responses at all.

I hope this helps!