Keeping Information in Context
Without context, words have no meaning, and the same is true for documents, in that often a wider context is required to fully interpret the information they contain. For example, a family photo is practically useless if you do not know who the people portrayed in it are, and likewise, a document that refers to the president of the US is of little use without knowing who held the job at the time the document was written. This becomes even more important when considering the long-term preservation of documents, as not only is human memory fallible, but over long periods the people accessing the documents will change (e.g. photos passed down through generations), as will their understanding and knowledge of the world. While preserving the context associated with a document is an important first step in ensuring information remains useful over long periods of time, we also need to consider how information evolves. Over any significant time period, the meaning of information changes. This evolution can range from changes in the meaning of individual words to more general terms or concepts, such as who holds a specific position in an organization. In this chapter, we look in detail at all of these challenges and describe the development of a conceptual framework in which context information can be collected, preserved, evolved and used to access and interpret documents. A number of techniques are presented showing real examples of context in action that fit within the framework, and applying to both text documents and image collections.