When designing cluster-randomized trials (CRTs), one important consideration is determining the proper sample sizes across levels and treatment conditions to cost-efficiently achieve adequate statistical power. This consideration is usually addressed in an optimal design framework by leveraging the cost structures of sampling and optimizing the…

Reviews the use of signatures to improve the performance of text searching and considers the use of signature trees to further accelerate text searching. Based on the analysis of experimental results, it is concluded that the improvement in text searching performance using signature trees outweighs the increase in required storage. (12 references)…

Introduces two distribution schemes that partition documents over multiple processors and the corresponding multiprocessor retrieval algorithms that match relevant documents to user queries. The suggested framework is based on a general purpose hypercube multicomputer architecture with a dedicated disk for each node. A timing analysis for the…

Discussion of relevancy in information retrieval systems focuses on an analysis of the efficiency of various cluster-based retrieval (CBR) strategies. A method for combining CBR and inverted index search is proposed that is cost effective in terms of time efficiency; and results of experiments are reported. (Contains 32 references.) (LRW)

The technical problems involved in obtaining Bayesian model estimates for the regression parameters in m similar groups are studied. The available computer programs, BPREP (BASIC), and BAYREG, both written in FORTRAN, require an amount of computer processing that does not encourage regular use. These programs are analyzed so that the performance…