Knowledge Representation and Reasoning

CHAPTER 12 VAGUENESS, UNCERTAINTY, AND DEGREES OF BELIEF

In earlier chapters, we learned how precise logical statements about the world, in many different forms, can be useful for capturing knowledge and applying it. However, when we try to emulate the more common-sensical kinds of reasoning that people do, we find that the crisp precision of classical logics may fall short of what we want. As we saw in Chapter 11, trying to represent what is known about a typical bird stretches our logical forms in one direction—not every bird has all of what we usually think of as the characteristics of birds in general. But there are additional needs in Artificial Intelligence that ask us to extend our representations in other ways.

Sometimes it is not appropriate ...