Perception of grade intervals.

Abstract

Stone and Sinnett (1968) presented pairs of grade intervals to college professors to be judged using a paired-comparison technique. The question asked of them was which member of each pair was phenomenally larger. Twelve intervals between A and F were judged, including intervals such as C+ to B-. They found the log of the phenomenal scale values best fit the physical A, B, C, D, F scale. These scale values fitted Thurstone's Case 111 rather rhan his Case V. Since pluses and minuses are not given in many colleges, would the same results be obtained using the conventional four-interval scale: AB, BC, CD, DF? The intent of this study was to investigate the relationship of the phenomenal to the physical grade scale in graduate students of educational psychology. Thirty-five graduate students in educational psychology were asked to judge which of each pair of grade intervals appeared larger. A = 4; B = 3; C = 2; D = 1; F = 0 anchors were given. All possible pairs were presented in such a manner as to minimize position effects. An alternate form of the task was presented 1 wk. later. Coefficients of consistence were computed for each S? The median coefficient was 1.00. Circular triads were infrequently noted. Analyses of variance of the frequencies of selecting each interval revealed an effect beyond the 5 per cent level (F = 19.21) of the physical grade (X) on the phenomenal ( Y ) . The trend was s~gniflcantly linear (F = 68.62). Tests for quadratic and cubic trends were also made. I: ratios were nonsignificant, 0.19 and 1.11, respectively. Adjusted z scale values were found to be AB = .000; BC = ,018; CD = .186; DF = .665. The Mosteller test was made to determine goodness of fit to Thurstone Case V. The nonsignificant x 2 was 0.02. The hypothesis of fit to Case V was accepted, there being equal discriminal dispersions for each interval. The absolute average discrepancy among the judges was .004, satisfactory for paired-comparison data. After 1 wk. Ss received an alternate form of the rask. The stability coefficient was 34 . Since both Ss and grade intervals differed from those in Stone and Sinnea's study, the data are not comparable. The present study indicates that higher marks have smaller phenomenal distances between them. As the intervals increase from high ro low grades the phenomenal distances increase. The most frequently occurring pattern of choices was: ALSmal l e s t , BC-Larger, CD-Larger rhan BC, DF-Largest. Perhaps to graduate students failure marks are the apogee of the academic universe but the orbits associated with A, B, C are less distinguishable and close to the perigee. On the other hand, the size of DF may be artifactual. It is the only interval in which a letter (E) next in alphabetical position is missing.