What is knowledge?

We all are aware that we are living in the Information Age, just as there have been ages of hunting and gathering, of agriculture and of industry in the preceding centuries and millennia. Information and knowledge shape our lives and our society in many ways.

This is now increasingly reflected in scholarship: terms such as information architecture, knowledge management and knowledge representation are increasingly common in the titles of conferences, books and educational programs. This book contributes yet another tile to this mosaic, by dealing with the conceptual arrange - ment of knowledge content.

However, before we get down to details we need to get a clear idea of what we are talking about. Obviously, this is a requirement in any domain, but it is even more necessary in the present case, as terms such as those used above, although suggestive, cover a particularly wide and fuzzy semantic space. When people from outside our field ask me about my research domain and I answer ‘knowledge organization’, their faces often express a mix of polite deference and perplexity about what exactly am I referring to.

Let us start with the first half of the term. What do we mean by knowledge?

Knowledge as representation of networks

Intuitively, we are aware that knowledge often refers to someone knowing something – that is, having developed some internal representation of certain external objects. That Maria knows the story of Christopher Columbus means that her mind has some representation of a sequence of events involving the navigator and his actions which led to the rediscovery of the Americas by Europeans.

The representation consists in a model of some set of entities and of links among them. While Columbus, his sailors, his maps and his ships were made of material substances, the notions in Maria's mind are immaterial ideas, recorded in a complex system of neural connections. Still, the material entities and the ideas modeling them are similar in terms of the network of relationships between their parts – they are isomorphic. Knowledge is thus a (usually simplified) reproduction of relationship networks in a different substrate. (This description differs from traditional philosophical definitions of knowledge as ‘true and justified belief ‘, although ‘truth’ corresponds in our description to isomorphism; a model that does not correspond to the represented object is a ‘false’ one.)