Using these two parameters there are four user types:

1. user who doesn't know, and knows he doesn't knows - this user has low understanding of how things work and has knows that, so he ask references for each and every action, while trying to keep a detailed record of how each action is performed. This type of user is easy to satisfy as it wont have a lot of expectations from the computer.
2. User who knows and knows he knows - this user is easy, it's a power user with actual knowledge who can actually be a local guru in his vicinity. From support point of view he can be cooperative and actually be a helping hand for his surroundings or there can be animosity where he is seen as negative influence.
3. User who knows but he thinks he doesn't knows - this user is a normally someone with some knowledge but who is unsure of it. This user can be guided, his confidence built and he can actually provide very important hints on real user needs.
4. User who doesn't know but thinks he knows - this is a fake power user, he will try to have to looks and uses of a real power user by mimicking but he doesn't have the actual knowledge of the reasons and the concepts. This user is the most difficult to treat as he wont accept authority and ask for reasons but lacks the foundation for actually understanding the situation. When presented with an option to learn, the user refuses on the ground of being un-appreciated.

Each of these type of users can be handled, some easier and some not so, but each one can teach you on human nature and the interactions between user and the computer.

In my experience, having an open mind for finding the right way of interacting with each user is a very enriching experience, who as provided me tools for creating valid communication with many types of persons. In a sense, support work was the first step in learning system engineering - learning communication skills.