how much has ralph changed since he's had his first assembly?
You will need to brainstorm this in two columns:
~one column in which to list characteristics of what Ralph was like at first
~second column in which to list his characteristics as of the end of the book (or whatever other time in the book you are thinking of).
Once you have his character traits listed in these two columns, you should be able to see the differences. These differences will indicate how much he's changed; and if there are few or no differences, then you can conclude that he hasn't changed much -- or at all!
Be sure to check out www.sparknotes.com/lit and read the character analysis if you need extra help.