I have the replaygain script installed for Amarok and it's working fine.  I have some questions about the settings.  On the page I downloaded the script from it describes the different ways of analyzing the files:

You can analyze a file, album or your whole collection from the playlist's context menu:
Apply Replaygain tags->
-- To selected files in track mode: tag one or more files (as selected in playlist) with their respective track gain (track mode).
-- To playlist in album mode: tag all files in the playlist with both album and track gain tags (album mode), as if the playlist is one album.
-- To entire collection using album tags: the script will group the files in the database using their "Album" tag, and scan each group in album mode.

Do all of these different methods scan each individual file the same way?  Or, if I scan selected files in track mode, and a different playlist in album mode, will they be scanned in different ways so that if I switch between album and track modes the volumes won't be constant? 

If I scan everything in track mode then does that mean I won't have the data I need to run in album mode?

Any clarification of this would be great.