Abstract: Granular computing is a tool dealing with imprecise, incomplete and uncertain knowledge, Just as a great umbrella，it may be regarded as a label of theories，methodologies，techniques，and tools that make use of granules. There is a fast growing and renewed interest in the study of granular computing. In this paper we analyze the characteristics of granularity from human recognition, and present granular computing models of quotient space theory. Then we introduce the main methods about granular computing, and carry on mutual compare with them.

Key words: Granular Computing, Quotient Space, Fuzzy Set, Rough Set

摘要： 粒度计算是一种用来处理不完全、不可靠、不精确、不一致和不确定知识的工具，它象一把大伞，覆盖了所有有关粒度的理论、方法论、技术和工具的研究，已成为人工智能研究领域的重要热点。本文从人类智能特点出发，分析了粒度的特征，提出了商空间理论的粒度计算模型。介绍了粒度计算的主要方法，并对这些方法进行了比较。

关键词: 粒度计算, 商空间, 模糊集, 粗糙集