Recent years have seen the development of a number of knowledge-based tools who's primary objective is to provide support to a human during the process of database analysis and design. However, whereas human designers are able to draw upon their experience and knowledge of the real world when performing such a task, knowledge-based database design tools are generally unable to do so. This has resulted in numerous calls for the development of tools that are capable of exploiting real-world knowledge during a design session. It has been claimed that the use of such knowledge has the potential to increase the appearance of tools intelligence, to improve the quality of the designs produced, and to increase processing efficiency. However to date, little if any formal evaluation of these claims has taken place, This paper presents an evaluation of one approach proposed to facilitate the system-storage and exploitation of real-world knowledge. The paper discusses how the dictionary approach has been exploited by a prototype tool providing support for the design of object-oriented databases. During testing, the use of the dictionary approach has been seen to result in an increase of the appearance of intelligence of the tool, and has improved the consistency and quality of the designs produced.