Your assignment is to pick a domain that you would like to represent, and construct a semantic theory of it by building an inference table. It will help you if you read the first three chapters in Scripts, Plans, Goals, and Understanding (SPGU). Read also the lectures especially, 4 and 5.

How to pick a domain:

Pick a technical domain like how to operate a machinery or  how something works. Look at How stuff works on the web.


Pick a social domain like "What to do on first date" or "Job Interview". 

How to build a table:

The rows of the table will be Actions, States of the system, or Mental States of the user. There should be at least ten of them. You do not need to have both States and Mental states, but it can help.

The columns of the table should be types of inferences. Pick the following or make your own: Result, Enable, Initiate, Reason, Function, Intervention.

Examples of inferences from the lectures:

Acts can RESULT in states (more properly, state changes).

States can ENABLE actions.

States or acts can INITIATE mental states.

Mental states can be REASONS for acts.

FUNCTION: Why do people desire to possess objects?  Usually, in order to perform their normal functions. John wants the book. JOHN PROBABLY WANTS TO READ IT.  

INTERVENTION: If an action in the world is causing (or will cause) undesired results, what might an actor do to prevent or curtail the action? The baby ran into the street.  Mary ran after him. MARY WANTS TO PREVENT THE BABY FROM GETTING HURT.

The cells in the table will have a mental state or action that results from the given inference. Many cells will be blank.

Those are only guidelines. You have to have at least 10 rows, and at least 6 columns, but you can substitute any type of inference from SPGU or the lectures 4 and 5, and you can even make your own. I suggest you start by writing down the rows. Once you get into this, you will discover that it is fun, and you'll have many more rows than 10. But if you do not share my enthusiasm, 10 is OK.


Hand in:

Please type, and hand in both hardcopy and email. Both.

No Extra Credit this time. ( I could not think of anything, but feel free to post suggestions on the newsgroup.)