Louis L. Thurstone
University of Chicago
It is the purpose of this paper to describe a new psycho-physical method for measuring the psychological or functional similarity of attributes. Its development was motivated primarily for the solution of a particular problem in the measurement of social attitudes and it is in terms of this problem that the new psychophysical method will be described.
Let each of a group of N individuals be labeled as to the presence or absence of each of n attributes. This means that we are dealing with N persons and that each of these persons declares the presence or absence in him of each of the n, attributes. It does not matter for our present purposes whether the declarations are made by these people for them-selves or by others for them. In our particular problem we are dealing with a list of n statements of opinion and each person has the option of endorsing or rejecting each of the n opinions. The statement of an opinion is here regarded as a description of an attribute and the subject merely indicates whether he possesses the attribute. A similar analysis might be made for a series of traits which are supposed to describe people along an extroversion-introversion continuum, an ascendance-submission continuum, and so on. Our primary interest is here in the attitude continuum.
We postulate, for verification, an attitude continuum for the n opinions. Let them describe different attitudes toward the church for purposes of illustration. Some of the opinions reflect attitudes very favorable and loyal to the church; others are neutral or slightly favorable, while still others are slightly or strongly antagonistic to the church. We want an objective procedure for ascertaining whether any particular set of opinions really behaves as a continuum when the endorsements are analyzed.