Ways of Dealing Reasoning with Uncertain Knowledge

Ways of Dealing Reasoning with Uncertain Knowledge:

We looked at knowledge and considered how different knowledge representation schemes allow us to reason. Recall, for example that standard or classical logics allow us to infer new information from the facts and rules which we have. Such reasoning is useful in that it allows us to store and utilise information efficiently (we do not have to store everything).

However, such reasoning assumes that the knowledge available is complete (or can be inferred) and correct and that it is consistent. Knowledge added to such systems never makes previous knowledge invalid. Each new piece of information simply adds to the knowledge.

This is monotonic reasoning. Monotonic reasoning can be useful in complex knowledge bases since it is not necessary to check consistency (as required in expert systems) when adding knowledge or to store information relating to the truth of knowledge. It therefore saves time and storage.

However, if knowledge is incomplete or changing an alternative reasoning system is required. There are a number of ways of dealing with uncertainty.

We shall consider some of them, briefly:

1. Dempster shaffer theory

2. Fuzzy reasoning.