A concept dictionary at EDR

The electronic dictionary created by the Japan Electronic Dictionary Research Institute, Ltd. (EDR) is made of several dictionaries, one of which is a concept dictionary. This dictionary describes the relationships between 400,000 concepts that have been introduced as word meanings from the word dictionary. Thus, each concept is one particular word meaning, and is represented by a sequence of 5 alphanumeric characters. Each word of the Japanese and English dictionaries is therefore connected to one or several concepts.

The concept dictionary contains:

• a concept list, with their identification number, one illustration of their meaning through an example sentence, and an explanation of their meaning;
• a concept classification that describes the "super/sub" binary relationships between concepts;
• concepts descriptions, that describe binary semantic relationships between concepts, e.g. agent-object or object-action.

Using these dictionaries for NLP tasks usually involves tools to navigate inside graphs, in order to understand the meaning of sentences written in natural language. Semantic disambiguation can for instance be obtained by searching the positions of ambiguous words in the concept graph, and by comparing these positions.