677	 Length of Strings for a Merge Sort	 Detailed statistics are given on the length of maximal sorted strings which result form the first internal sort phase of a merge sort onto tapes. It is shown that the strings produced by an alternating method i.e. one which produces ascending and descending strings alternately tend to be only three-fourths as long as those in a method which produces only ascending strings contrary to statements which have appeared previously in the literature. A slight modification of the read-backward polyphase merge algorithm is therefore suggested.
