ABSTRACT
The processing and expression of unascertained information are important research topics in the information age. The uncertainty that people encounter at the earliest stage is random, and encompasses probability theory, mathematical statistics, and other subjects. Along with the development of production, science, and technology, the fuzziness resulting from unclear definition has been gradually recognized and fuzzy mathematics is the tool that handles fuzzy information. In the 1980s, scholars studied information that is partly known and partly unknown, namely, gray information. Compared with random fuzziness, gray has less known composition, the indetermination contains higher degree, and the gray set and the gray number constitute the foundation of gray mathematic theory. When engaged in construction engineering theory, Wang Guang Yuan [15] discovered an uncertainty that is different from the random, fuzziness, gray, called an unascertained property. This kind of indetermination mainly is from purely subjective understanding of indetermination that results from decision makers not knowing the complete state and mathematical relation of a situation. From actual decision-making problems, this chapter puts forward a new method of AHP. Its meaning and mathematical expression are similar to the unascertained number and then the unascertained number is adapted to AHP.
