User Modeling human-computer interaction

2.2 The human factor
In the interaction of humans and computers we normally have two different views. On
the one hand we have the user with his so called ”mental model” of the computer system.
On the other hand we have the computer system with the ”user model” and its view of
the user.
Mental Model The so called ”mental model” of a user is the knowledge about the
components of a system and the experience of how to use the computer system properly
(see [CO88]).
User Model If we want an personalized computer system we need to build a ”user
model” so that the system knows the preferences, capabilities and skills of the user.
If we put this two views together, we get a system that reacts in two different ways.
The user can interact with the system and use it to perform his tasks, because of his
knowledge about the computer system. The system ”knows” the intention and goals
of the user and can adapt to the needs of him, because of the information in the user
model.
2.3 Information about a user
As we have seen, if we want a personalized computer system that adapt to the needs of a
user, we must collect some information about the user. We can divide these information
into three types (see [Kob04] and [Fis01]).
user data First we have the user data which is the information about the user himself,
e.g. his knowledge, skills and capabilities. The interesting thing with this type of
information is the intention and goal of the user when he uses a computer system.
I would like to show the importance of this information by an example. If a user selects a
new document in a word processor from a template to gererate a new letter, the system
should infer the intention and possible goals (in this case the tasks a user wants to
perform). Because normally the generation of a letter includes the lookup of an address
in a personal addressbook or a public one to fill in the destination information. Another
task is to print out the finished letter to put it in a cover and send it to its destination.
usage data The example leads us to the second type of information that must be
collected from a user – the usage data. In the example we observe the user and recognizes
that he wants to write a letter. Now we can look up his usage regularities to infer that
after he has looked up the destination address he wants to print out the document.
environment data The last type of information that can be captured is what kind of
software the user normally use, and what type of hardware is available for a user.
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