Ontology-Based Constraint Recognition for Free-Form Service Requests

Automatic recognition and formalization of constraints from free-form service requests is a challenging problem. Its resolution would go a long way toward allowing users to make requests using free-form, natural-language-like specifications. In this paper, we address this challenge by offering an ontology-based, semantic-data-modeling approach to recognize constraints in free-form service requests. We encode domain information such as possible constraints and instances within a domain ontology in terms of object sets, relationship sets among these object sets, and operations over values in object sets and relationship sets. Our system recognizes the constraints in a service request by finding the domain ontology that best matches the request and then by using relationships and operations relevant to the request in the matched ontology to generate the service-request constraints. In experiments conducted with our prototype implementation, our system achieved an average of 96% recall and 99% precision.