Declaration Field

See also: Why was the question being asked

The first line of a parameter declaration takes the form of the keyword parameter, the name of the parameter, optionally followed by a colon, : and then some text describing the parameter. The syntax for the declaration field is:

<declaration field> ::= parameter <parameter-name> [:] <description-text>

The description text is used to generate replies when the expert system user employs ESTA's facility to ask HOW a certain value was established or WHY a certain piece of advice was given. Thus, the person responsible for writing a knowledge base should take care that the descriptions read well given the sentence-schemes for explanations automatically generated by ESTA.

For boolean parameters the ESTA phrase is:

The objective is to find out whether <description-text>

For number, text or category parameters the ESTA phrase is:

The objective is to establish the value of <description-text>

Examples

Using the following parameter declarations:

parameter owns_car 'you own a car'

type boolean

parameter height_cm 'your height in cm'

type number

ESTA would generate the following explanations on command from the user:

The objective is to find out whether you own a car

The objective is to establish the value of your height in cm