Computerized Sorting Program for the Maryland House of Delegates
THE MATRICES used in chapters 3, 5, and 20 were constructed by a computer sorting operation that compared the record of each delegate with that of every other over the course of the legislative session. The House of Delegates annually recorded about 100 roll calls, but not all were used. Particularly lopsided votes were eliminated because there was no substantial area of disagreement (the threshhold ratio used was 5 to 1). Roll calls that were purely personal or local in nature were also eliminated. So were votes that seemed to duplicate one another, such as procedural moves or slight changes in wording.
Among the legislators themselves two requirements were imposed. The first was a pair-wise voting threshhold of 50 percent. The program considered only those pairs of legislators who participated in at least half the roll calls and thus had an opportunity of agreeing or disagreeing a significant number of times. The second was the agreement threshhold required for placement in the matrix. Two threshholds were used 70 and 80 percent. The latter, which is