A monte carlo evaluation of interactive multidimensional scaling

Interactive Scaling with Individual Subjects (ISIS) developed by Young & Cliff [1972], is a method involving interaction between subject and computer in real time to determine which judgments made by the subject are critical to the definition of a dimensional structure. The procedure is based on the mathematical fact that it is possible to define a space ofR dimensions in terms of only the interpoint distances between all stimuli being scaled and a subset of (R+1) of these stimuli. For errorless judgments, any subset of (R + 1) stimuli is appropriate. However, fallible data require that the subset consist of stimuli that are maximally dissimilar, and the ISIS procedure is designed to obtain such an optimum subset (a basis).This research evaluates a modified version of ISIS with respect to (a) a metric MDS analysis based on all possible pairs of the stimuli, and (b) a metric MDS analysis based on a subset of one-third of the possible pairs, or about the same number as that required by ISIS. Results show that the ISIS method achieves better fit than (b) at low error levels, and may also achieve better fit than (b) at higher error levels if the size of the basis is increased. The more stimuli in the basis the more indices of fit approach those of (a).A new method of introducing error in MDS studies is used in the evaluation.This research is based in part on the doctoral dissertation of the first author, and was supported by research grant MH-16474 from the National Institute of Mental Health, Public Health Service.     

Balance,agreement, and attraction in hypothetical social situations

Sixty subjects rated hypothetical P-O-X situations involving two persons and an unspecified but important “thing” for pleasantness, tension, and consistency. The situations varied in terms of whether P and O liked or disliked each other and whether P and O agreed or disagreed regarding X. Half of the subjects rated eight situations used by Gutman and Knox (Journal of Personality and Social Psychology, 1972, 24, 351–357) in which a unit relation was induced between P and O by describing them as necessarily having to continue interacting with one another in the future. The other half of the subjects rated situations that were identical to those of the unit condition, except that stipulation of continued interaction was omitted, so that no unit relation was specifically induced. Results showed that preferences for agreement and attraction were stronger for pleasantness and tension ratings than for consistency ratings, while the preference for balance was stronger for consistency ratings than for pleasantness and tension ratings. When no unit relation was specified, the balance preference increased, whereas the attraction preference decreased. Moreover, the effect of attraction decreased more from the unit to the no unit condition for pleasantness than for tension ratings and more for tension than for consistency ratings. The results underscore the need to consider the influence of both the described characteristics of hypothetical social situations and the type of dependent measure employed on the weighting of preferences for balance, agreement, and attraction.     

Decision-Making in Married and Unrelated Couples

The decision-making performance of 20 married and 20 synthetic couples, all college students, was compared using the Ferreira-Winter Questionnaire technique. Married couples showed (a) greater spontaneous agreement with each other prior to conjoint discussion, (b) less politeness, (c) more intrusive interruptions, and (d) a lesser exchange of explicit information between husband and wife. Although married couples arrived at more "democratic" or representative decisions in a faster time, this was due to their greater degree of prior shared values and interests. The effects of the history and context of the relationship between subjects upon their pattern of communication and possible contrasts between normal and abnormal couples are discussed.     

A system for accurately measuring articulatory durations which is not reset by any included silent periods

A device is described that accurately measures duration of phonation or articulation without being reset by intervening silent periods or pauses, which may be within the range of 10 to 1,000 msec. Thus, it is possible to time the overall duration of single sounds, syllables, single or multiple words, even though periods of silence are included. Input can be direct or recorded, the ancilliaries being a voice-operated switch and a chronoscope.     

Facial attractiveness and juvenile delinquency among black and white offenders

Facial pictures of black and white delinquents were significantly less attractive than pictures of corresponding groups of high school students, as judged by same-race raters. Significant differences were found among the white delinquents, but not among the black, for Quay's four behavioral dimensions of delinquency. Black delinquents were significantly darker in skin color than the black high school students, and lightness of skin color was positively correlated with physical attractiveness ratings made by both black and white raters, indicating that neither race has yet assimilated the saying black is beautiful. This and other evidence suggest that facial attractiveness may be causal in delinquency.These studies were conducted with the cooperation of the staff of the Robert F. Kennedy Youth Center, Federal Bureau of Prisons, U.S. Department of Justice. The center is not responsible for the contents of this report; the report does not necessarily represent the Center's views. The portion of this paper dealing with the white offenders was presented at the meeting of the Eastern Psychological Association, Boston, Massachusetts, April 1972.The authors would like to thank Hayne W. Reese for his assistance.     

Conformity as a function of task generalization and relative competence

Subject correctness and group agreement were varied for college subjects engaged in a light discrimination task. On another task, employing multiple-choice questions about Canada, the dependent variable of conformity was assessed to examine generalization of relative competence formed on the light discrimination task. It was seen that (1) relative competence was seen to mediate conformity for a specific task (Canadian Knowledge Inventory), but did not generalize across tasks (i.e. from the light discrimination task to the Canadian Knowledge Inventory); (2) with respect to the Canadian Knowledge Inventory, subjects who perceived themselves as more competent than the group did not conform as much as those who either perceived themselves as less competent than or as competent as the group; (3) the experimental manipulations did not affect conformity, further supporting the findings that perceived competence does not generalize across classes of tasks; (4) females conformed more than males: and (5) nonsuspicious subjects conformed more than suspicious subjects.     

VALUE SYSTEMS OF STUDENTS IN PAPUA NEW GUINEA AND AUSTRALIA

The Rokeach Value Survey was administered to 12 groups of indigenous respondents fluent in the English language and enrolled in tertiary institutions and training programmes in Papua New Guinea (over 1,100 subjects). Average value systems of these respondents were compared with those of three Australian student groups (secondary and tertiary). Marked differences were found in the relative importance assigned to particular values. Values assigned relatively high importance by the Papua New Guinea groups were discussed in relation to lower-order safety and security needs that may become salient in a developing country, and in terms of the traditional culture and the history of Papua New Guinea, especially the missionary influence, the extended family and wantok (”one-talk”) systems, possible expatriate influence on occupational roles, and present concern with emerging nationhood. Values assigned relatively high importance by the Australian groups were discussed in relation to higher-order needs that might become prepotent in a more affluent society. Factor analyses indicated that all 12 groups in Papua New Guinea were fairly similar in their average value systems.     

Modification of depth judgment following exposures to magnification of uniocular image: Are changes in perceived absolute distance and registered direction of gaze involved?

Two studies were designed to determine whether the perceptual learning that has been demonstrated to occur during exposure to uniocular image magnification can be explained by either a modification in the perception of egocentric distance or the direction of gaze. Experiment 1 was designed to determine whether exposure to uniocular image magnification produces changes in perceived absolute distance. Experiment 2 tested the possibility that exposure to uniocular image magnification modifies the registration of direction of gaze. The results showed that, despite the occurrence of adaptive shifts in perceived depth, no significant changes in perceived absolute distance or in registered direction of gaze occur. These findings bolster confidence in the hypothesis that adaptation to uniocular image magnification is the result of a recalibration of retinal disparity.     

Interactive scaling with individual subjects

A metric multidimensional scaling (MDS) procedure based on computer-subject interaction is developed, and an experiment designed to validate the procedure is presented. The interactive MDS system allows generalization of current MDS systems in two directions: (a) very large numbers of stimuli may be scaled; and (b) the scaling is performed with individual subjects, facilitating the investigation of individual as well as group processes. The experiment provided positive support for the interactive MDS system. Specifically, (a) individual data are amenable to meaningful interpretation, and they provide a tentative basis for quantitative investigation; and (b) grouped data provide meaningful interpretive and quantitative results which are equivalent to results from standard paired-comparisons methods.This report was supported in part by a PHS research grant, No. M-10006, from the National Institute of Mental Health, in part by a Science Development grant, No. GU-2059, from the National Science Foundation, both granted to the Psychometric Laboratory at the University of North Carolina, and in part by a PHS research grant, No. MH-16474, from the National Institute of Mental Health, Public Health Service, granted to the second author. The major portion of this research was performed while the second author was the L. L. Thurstone Distinguished Fellow at the Psychometric Laboratory of the University of North Carolina while on leave from the University of Southern California. The authors are indebted to Amnon Rapoport and Thomas S. Wallsten for their critical evaluations of an earlier version of this report. While this paper was entirely a cooperative effort on the part of both authors, the first author was primarily responsible for the algorithms, and the second for developing the mathematical model.