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invoke_service_query

Calls the Service Interface query associated with a question and makes its answer available to the dialogue.

<invoke_service_query type="wh_question" predicate="price"
                      min_results="1" max_results="2"/>

Attributes and children

Attribute Default Meaning
type wh_question Question type: goal, wh_question, kpq, alt_question, or yn_question.
predicate — Required for a predicate-backed WH question.
min_results 1 Minimum number of expected results.
max_results 1 Maximum number of expected results; set above one to accept multiple results.

A yes/no question can use a proposition child; a KPQ uses embedded_question; an alternative question uses alt children. The item can appear in a plan, postplan, or conditional branch.

Behavior and usage

The service query returns an answer that becomes known to the system. If the question is a goal question and the answer is known, the system can provide the answer to the user. When max_results is greater than one, the service may return multiple results. Declare the queried ontology predicate with multiple_instances="true" if more than one fact for that predicate must be retained.

Examples

WH query:

<invoke_service_query type="wh_question" predicate="price"/>

Allow two results:

<invoke_service_query type="wh_question" predicate="available_animal"
                      min_results="2" max_results="2"/>

Yes/no query:

<invoke_service_query type="yn_question">
  <proposition predicate="need_visa"/>
</invoke_service_query>

KPQ form:

<invoke_service_query type="kpq">
  <embedded_question type="wh_question" predicate="destination"/>
</invoke_service_query>

See Service Interface queries and Findout.