About Browser Cache in IE

Recently i have observed that IE is making duplicate connections to get the same js file if it included twice. After making some experiments, I came to know that there is difference between Ctrl+F5 (Hard Refresh) and F5 (Refresh)

Ctrl+F5 (is intended to abandon all cached content and just retrieve all content from the servers again.)
In this case browser will overwrite the cache and it will not add the "If-modified-since" header to the request because of which it will get the file from the server everytime.

F5:
In this case browser by default adds the "If-modified-since" header to the request which will make the browser to get it from the cache.

So while taking Performance Readings in case of IE, we should be doing somethign like this:
1. Clear the cache.
2. Just F5(refresh) to get the actual response and normal browser behavior.