A SAGTORIAL investigation OF SPEED OF PERCEPTION OF STUDIOS DIFFERENCES by Charles Alan Boswell \ ^ - A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Psychology in the Graduate College of the State University of Iowa August 1950 State University of Iowa LIBRARY ProQuest Number: 10598584 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10598584 Published by ProQuest LLC (2017). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106 - 1346 T ^ b O ° .6THT CO jG» dL» ACiaJa^DG^KTS The author Is indebted, first of all, to Professor Harold P* Bechtoldt, whose careful supervision during all phases of the investiga tion is considered invaluable* Grateful acknow ledgment is also made to Dr* W« Grant Dahlstrom for assistance during the preparation of the manuscript, to the College of liberal Arts of the State University of Iowa for financial as sistance and to my wife, hois B* Boswell, for constant encouragement and help* TABLE OF COWENTS Chapter Page I* Introduction ..................... 1 Utilization of Response Consistencies and Inconsistencies ......................*......... 2 Use of Factor Analysis in Studying Trait Uniformities .............................. 4 Results of Factor Analysis Studies 6 The Perceptual Speed Domain . . . .................... 8 The Factor .................................. 11 Statement of the Problem ......... 17 II. She Investigation.................. 25 The Subjects........................ 23 The Testing Procedure ........... 23 The Tests ........... 24 The Factor Analysis ........... 36 III* Results and Discussion .................... 40 The Factors ............. * 40 Discussion ......... 61 Problems for Further Investigation....................64 I?. Summary and Conclusions ...................... 67 Bibliography ......... 71 Appendix A ...................... 75 Appendix B ........... 84 iii ThBlE OF TABIE3 Table Page X. Uae Test Battery................... £1 II* Simplified Rotated Factorial Pattern ........... 39 III# Data on the Subjects . . . .. . ........................ *......... 74 I?* Produet-Moment Correlations Between the Variables ......... . .......................................... 75 V# Arbitrary Orthogonal Factor M atrix ............. 78 VI. The Transformation Matrix ............ 79 ?II. Cosines of the Angles Between the Reference Vectors .......................... 80 rax. The Rotated Factor Matrix ................................. 81 IX. Distribution of Hath Factor Residuals . . . . ............. 82 X. Correlations Between the Primary Vectors ......... 85 iv 1 Chapter I INTRODUCTION During the last half century of the history of psychol ogy a considerable amount of psychological endeavor has been di rected toward the study of Individual differences. The mental test movement and the personnel, educational, and olinical psychological investigations are well known examples of the types of activities dealing in large part with individual differences. As a result of the research in these areas, a number of er^irical consistencies have been achieved together with some useful or pragmatic relations between response attributes and sensory thresholds, rates of acqui sition of new habits, the effects of different classes of incentives, and the changes in the stimulus dimensions. The empirical consistencies, in turn, have presented a challenge to some psychologists to formulate constructs which would account for the relations among the observations. Differences in absolute or difference limens, in asymptotic as well as initial per formance levels, in incentives or in experiences, have been proposed by many experimental psychologists as accounting for the observed differences in performances. Other investigators, primarily those in the "testing" fields, have tended to express the observed response consietencies in terms of constructs defined by the responses ob tained under specific stimulus conditions. 2 Utilization of Besoonse Consistencies and Inconsistencies Studies of the relations between performance measures and variations in the stimulus conditions have shown that individuals who perform in some specified way (say, most rapidly) in one activity may not do nearly so well in some other task, even when the two tasks appear superficially to be quite similar* For other types of active ities, individuals tend to maintain the same rank orders for the set of tasks, those who perform rapidly or accurately in one situation demonstrating similar relative performances on a number of other tasks* The contrast between the invariance of the rank ordering of individuals by one class of operations and the absence of such stability when some relevant or significant change is introduced into the defining operations raises the possibility of describing behavior in terms of these changes in the stimulus situations or in terms of constructs defined by such stimulus variations* The factor analysts and personnel psychologists have tended to express these systematic shifts in the rank orders in terms of response inferred constructs, such as traits, abilities, Interests, etc*, rather than in the form of stimulus variables per se. The implications of these constructs is that the traits or noperational or functional unities," as they are sometimes called, represent stimulus-response mechanisms, the 3 operation of which Is reflected in the performance of individuals on a variety of tasks. The constructs themselves are defined by the specification of the operations and stimulus conditions which can be shown to be influential or relevant* !*©♦, those procedures and conditions which make significant contributions to the variance of the behavior evaluations* The several individuals are considered as having different mounts of skill in these different response mechanisms* The formu lation in terms of traits or functional unities rather than stimulus dimensions alone seems justified at the present state of knowledge by the existence of the conspicuous differences in performance asso ciated with even "slight* changes in the stimulus variables* The stimulus dimensions for many tasks my not be amenable at present to systematic experimental variation. Furthermore, the relevant experi mental conditions and the effects attributable to changes in the stimulus dimensions are nearly all unknown at present* The eventual resolution of the observed differences in performance in specific trait In terns of the experimental conditions associated with the de velopment of the trait or with the physiological characteristics of the organism can be considered goals of soma psychologists interested in individual differences* The trait or functional unity approach may provide, however, a basis for the prediction and control of human behavior in a number of activities prior to the reduction of trait 1 concepts to other perhaps more basic terms* Guilford (8) and Thurston© (IS) have pointed out how a rational approach to test construction and differential prediction can be made through the use of trait constructs* They suggest that by isolating the common traits or abilities which are called upon in educational and employment situations, mare effective job analy ses and differential predictions may be made. The trait constructs should lead to a more nearly logical or systematic preparation of the selection tests rather than the present largely en$>irical one based on trial and error methods. Guilford even suggests in a per haps unduly enthusiastic passage, that statements of the factorial con$>osition of a test are of greater significance in applied psy chology than those describing its reliability or empirical validity (8, page 457 }* Use of Factor Analysis in Studying aaaae tans ssskcsesssbs rTBC.TsstrrrBrja apes TTait Uniformities The search for, and operational definition of, tar aits having some degree of generality (i.e., a common ordering of per formance evaluations obtained from two or more situations) are char acteristic of the factor analysis method of investigating the uni formities In behavior* The psychologist using these methods of analysis will formulate his hypotheses in terms of skills, habits, 5 or abilities which will either augment, reduce, or be associated with performances In some class of stimulus situations defined, say, by the type of instructions, the method of presentation of the stim uli, the method of response, the arrangement of the materials, the number of repetitions, the "content" or nature of the stimuli, etc, the factor analysis approach constitutes a basic explora tory tool} the results of the investigation are considered as pro viding indications of the relevant sources of variance common to a variety of tasks* These methods of investigation emphasise the de termination of the traits possessing the greatest stability (invari ance} and generality (scope of a common factor)} such traits should provide the greatest number of significant relations# The definition of a functional unity by the procedure of factor analysis involves no assumption as to the origin of the trait} the source of the response consistencies may lie in the cultural or physical environment or in the physiological structure of the indi vidual# The trait may be acquired or inherited, easily modified or resistant to change, specific to a restricted class of situations or possessing considerable generality# They may represent differential rates of acquisition of habits, differential asynspbotic levels of performance or differences in the amount or conditions of training#