Interested in people's feedback.

How well can users visiting a web site conceptualise or create a mental
model (after about 30 minutes of use) of the structure and organisation
of that site?

There is alot of information on how to improve navigation and structure
of a site (understanding users tasks etc), but I cannot find much
information on the tools and techniques that could be used to map the
structure, pages and relationships between different parts of a site
after a user has been using the site online.

I read about the card sort technique as one method used to find out how
users might group, categorise information. But this relates more to
grouping and categorising information before the site has been

But what tools do you use to understand the user's model of an web site
that is already online?

Thanks in advance