Explain scripts in details with example for artificial intelligence

Scripts

A script is a structured representation describing a stereotyped sequence of events in a particular context.

Scripts are used in natural language understanding systems to organize a knowledge base in terms of the situations that the system should understand. Scripts use a frame-like structure to represent the commonly occurring experience like going to the movies eating in a restaurant, shopping in a supermarket, or visiting an ophthalmologist.

Thus, a script is a structure that prescribes a set of circumstances that could be expected to follow on from one another.

Scripts are beneficial because:

• Events tend to occur in known runs or patterns.

• A casual relationship between events exist.

• An entry condition exists which allows an event to take place.

• Prerequisites exist upon events taking place.

Components of a script

The components of a script include:

• Entry condition: These are basic condition which must be fulfilled before events in the script can occur.

• Results: Condition that will be true after events in script occurred.

• Props: Slots representing objects involved in events

• Roles: These are the actions that the individual participants perform.

• Track: Variations on the script. Different tracks may share components of the same scripts.

• Scenes: The sequence of events that occur.

Describing a script, special symbols of actions are used. These are:

Example:-Script for going to the bank to withdraw money.

SCRIPT : Withdraw money

TRACK : Bank

PROPS : Money

Counter

Form

Token

Roles : P= Customer

E= Employee

C= Cashier

Entry conditions: P has no or less money.

The bank is open.

Results : P has more money.

Scene 1: Entering

P PTRANS P into the Bank

P ATTEND eyes to E

P MOVE P to E

Scene 2: Filling form

P MTRANS signal to E

E ATRANS form to P

P PROPEL form for writing

P ATRANS form to P

E ATRANS form to P

Scene 3: Withdrawing money

P ATTEND eyes to counter

P PTRANS P to queue at the counter

P PTRANS token to C

C ATRANS money to P

Scene 4: Exiting the bank

P PTRANS P to out of bank

Advantages of Scripts

• Ability to predict events.

• A single coherent interpretation maybe builds up from a collection of observations.

Disadvantages of Scripts

• Less general than frames.

• May not be suitable to represent all kinds of knowledge