Optimizing the Polyphase Sort Various dispersion algorithms for the polyphase sorting procedure are examinedhe optimum algorithm based on minimizing the total number of unit strings read is displayed. The logic of this algorithm is rather complicated; hence, several other new dispersion algorithms with more straightforward logic are presented. Of the simple dispersion algorithms discussed, the Horizontal is best. It does approximately one-fourth to one and one-half percent less reading and writing than most algorithms in use today. An additional two and one-fourth to three percent improvement can be achieved by utilizing the Modified Optimum Algorithm. This algorithm is relatively straightforward, but it requires a fairly close estimate of the total number of unit strings before the dispersion begins. CACM November, 1971 Shell, D. L. sorting, polyphase sorting, dispersion algorithms, optimum dispersion algorithm, repetition operator 5.31 CA711103 JB February 2, 1978 11:39 AM 1117 4 2146 1117 4 2146 2017 4 2146 2017 4 2146 2017 4 2146 2146 4 2146 2146 4 2146 2146 4 2146 2146 4 2146 479 4 2146 677 4 2146 860 4 2146 861 4 2146 862 4 2146 863 4 2146 299 5 2146 2146 5 2146 2146 5 2146 2146 5 2146 862 5 2146 863 5 2146 861 5 2146