Assuring Retrievability from Unstructured Databases by Contexts

In an unstructured database the data is a collection of facts that does not adhere to any schema. Such a database does not require any initial design and can thereff)re evolve freely to accommodate new applications. It is particularly suitable for information which is diverse and idiosyncratic, such as when we want to store everything known on a particular topic. Unfortunately, this freedom also means that similar information may be entered in different forms. This may cause severe problems when retrieval is attempted, as some of the data may appear to have been "lost * in the database. In this paper we propose a method to solve this problem. Each database fact must be supported by a context in the database, in the form of several other facts. When an attempt is made to add a fact to the database, the existence of a suitable context is verified, or is extracted from the user in a simple dialogue. Thus, the database still retains the flexibility of unstructured databases, but problems of multiple representations are usually prevented. 1