Guttman Scale Analysis

Guttman scale analysis may be considered as two inseparable endeavors: (1) to ascertain if a set of stimu!'i are unidimensional in nature and if so, (2) to tank order respondents along the same continuum based on their reaction to toe stimuli. For example, suppose a set of four attitude statements (S1-54) are constructed such that similarity of content exists (e.g. all concern attitude toward importance of college education) and that the stimuli have an intrinsic rank order (i.e. affirmative response to 11 statement indicates a more or less favorable attitude than an affirmative response to a second statement). Given such conditions, a Guttman type scale is tenable provided (1) a negative response to the lowest ordered stimu1us t let's say 81, precludes a positive response to 52-54 and in turn, a negative response to 52 precludes affirmation of 53-S4 while a nega tive response to 53 precludes affirmation of S4 and (2) knowledge of an individual's scale score equal to the number of affirmative responses predicts without error his responses to each item in the ordered set. Tables 1 and 2 below present a positive and negative illustration of the above conditions, respectively. Referring to Table 1, not only do the stimuli possess rank order along some continuum but also a scale score specifies an individual's rank order along the same continuum, that is, an individual with a higher score ranks as high or higher on every statement in the ordered series than an individual with a lower scale score.