Hierarchical Storage in Information Retrieval A probabilistic analysis is employed to determine the effect of hierarchical storage organizations on information retrieval operations. The data storage hardware is assumed to consist on n-levels of linearly connected memory hardware with increasing data access times and increasing data storage capabilities. A system might, for example, consist of fast semiconductor memory, computer core memory, extended core storage, disk memory, and data cells. Equations are derived to predict the effect of such a system on data access times using sequential files, random access files, and structured files employing multiple-hierarchical linked lists. CACM May, 1973 Salasin, J. information retrieval, hierarchical storage 3.70 3.72 3.73 3.74 3.79 3.90 6.20 6.34 CA730504 JB January 24, 1978 8:48 AM 2516 5 2516 2516 5 2516 2516 5 2516