2373	 Properties of the Working-Set Model	 A program s working set W t T at time t is the set of distinct pages among the T most recently referenced pages. Relations between the average working-set size the missing-page rate and the interreference-interval distribution may be derived both from time-average definitions and from ensemble-average statistical definitions. An efficient algorithm for estimating these quantities is given. The relation to LRU least recently used paging is characterized. The independent-reference model in which page references are statistically independent is used to assess the effects to interpage dependencies on working-set size observations. Under general assumptions working-set size is shown to be normally distributed. working-set model paging paging algorithms program behavior program modeling
