Number of Previous Accesses

Using number of previous accesses made to a document is a good indication as to whether the document will be requested in future. However, this cannot be used alone as the deciding factor as it does not allow aging of a document i.e. a document which has been accessed many times say 18 and after that not accessed at all for along time say for about 3 weeks will probably not be accessed again but still be retained in the cache.