In order to make this information accessible to users of the knowledge system it must be represented in a domain model which allows a representation that combines domain specific knowledge with an appropriate amount of world knowledge. A prerequisite for the analysis of natural language questions is specific knowledge of the domain plus a certain amount of knowledge of the world referred to by the questions. The database registers information about employees, customers, products, complaints etc. Each box in the diagram represents a type of entity. Each entity type is characterized by a number of attributes.
Employees have salaries, positions, sell products, etc.
Relationships as these are expressed by rhombs in the diagram. For practical reasons, the rhombs have no names in the diagram, as we are not going to focus on these relationships in the present context. This key makes it possible to access all the information concerning related entities, i.e. related tables. Some of the attributes, which were not included in the diagram, can be seen in the tables where they appear as names of the columns. In order to ensure the easiest possible retrieval of information from the database, two views concerning employees and sales activities of the company were created.