Definition Frames: Using Definitions for Hybrid Concept Representations
Table 1: Annotated Relations for 50 Wikipedia Sentences.
['[BOLD] Relation', '[BOLD] Num Sentences']
Similar to work on definitions, relation extraction focuses on detecting a set of important relations between terms. Those concepts are selected from the set of all nominal synsets from WordNet that are linked to Wikipedia, while for the sentences/definitions we use the first sentence of Wikipedia. From those annotations we observed that most definitions use the isA relation combined with a Differentia type relation and that certain relations can only be used on concepts with specific semantic types. As an example, the cause relation can only be used on events, while the madeOf relation on physical entities. Some other structures used as Differentia include adjectives, topics and analytical descriptions of processes.