Test theory without an answer key

A general model is presented for homogeneous, dichotomous items when the answer key is not known a priori. The model is structurally related to the two-class latent structure model with the roles of respondents and items interchanged. For very small sets of respondents, iterative maximum likelihood estimates of the parameters can be obtained by existing methods. For other situations, new estimation methods are developed and assessed with Monte Carlo data. The answer key can be accurately reconstructed with relatively small sets of respondents. The model is useful when a researcher wants to study objectively the knowledge possessed by members of a culturally coherent group that the researcher is not a member of.This research was supported by NSF Grant No. SES-8320173 to the authors. We gratefully acknowledge comments and suggestions from John Boyd, Tarow Indow, and Kathy Maher as well as the editor and several anonymous referees.     

Sample size determinations for the two rater kappa statistic

This paper gives a method for determining a sample size that will achieve a prespecified bound on confidence interval width for the interrater agreement measure,. The same results can be used when a prespecified power is desired for testing hypotheses about the value of kappa. An example from the literature is used to illustrate the methods proposed here.     

Generalized approaches to the maxbet problem and the maxdiff problem,with applications to canonical correlations

Van de Geer has reviewed various criteria for transforming two or more matrices to maximal agreement, subject to orthogonality constraints. The criteria have applications in the context of matching factor or configuration matrices and in the context of canonical correlation analysis for two or more matrices. The present paper summarizes and gives a unified treatment of fully general computational solutions for two of these criteria, Maxbet and Maxdiff. These solutions will be shown to encompass various well-known methods as special cases. It will be argued that the Maxdiff solution should be preferred to the Maxbet solution whenever the two criteria coincide. Horst's Maxcor method will be shown to lack the property of monotone convergence. Finally, simultaneous and successive versions of the Maxbet and Maxdiff solutions will be treated as special cases of a fully flexible approach where the columns of the rotation matrices are obtained in successive blocks.The author is obliged to Henk Kiers for computational assistance and helpful comments.     

Has the time come to rehabilitate Gestalt theory?

Summary The distinction is drawn between the metatheoretical commitments of Gestalt theory and their instantiations in explicit theory. It is argued that the metatheoretical commitments of Gestalt theory reflect important insights which might have served as the foundation of a theory of perception that avoids a number of the major difficulties associated with constructivism and the theory of direct perception. For this reason rehabilitation of the reputation of Gestalt theory is urged. In the concluding section certain similarities between the foundational premises of Gestalt theory and parallel distributed processing approaches are noted.The contents of this paper were presented initially at a symposium on perceptual theory in honor of Irvin Rock which convened in Washington, DC, on the occasion of the 1986 meetings of the American Psychological Association     

Sleep in the dove Zenaida asiatica

Electrographic and behavioral observations were made in five adult birds of the genus Zenaida asiatica. Five different vigilance states were quantitated: (1) Active waking (Aw) was characterized by constant behavioral activity; the nuchal electromyogram was tonically active with bursts associated to movements. The electroencephalographic pattern was low voltage and high frequency. (2) Quiet waking (Qw) was characterized by diminished behavioral activity and the EEG pattern was similar to that of Aw. (3) Drowsiness (D) was characterized by behavioral calm. Frequency of cerebral activity diminished progressively, but there were short periods of desynchronization corresponding to brief awakenings. (4) Slow wave sleep (SWS); during this period there was behavioral rest and EEG pattern of continuous slow waves and the nuchal EMG was tonically reduced. Spindles of sleep were not observed. (5) Paradoxical sleep (SP), behaviorally characterized by phasic manifestations consisting of noddings originated by rapid falling down of head and bursts of rapid eye movements. EEG activity was like that of waking state. EMG activity was maintained at the same level as during SWS but sometimes it decreased lightly. Total atonie was not observed. Sleep percentages were higher when recordings were done during the nocturnal period.     

Effects of aging and task difficulty on divided attention performance

We report two experiments that compare the performance of young and older adults on perceptual-motor tasks involving division of attention. Previous studies have shown older people to be especially penalized by divided attention situations, but the generality of this finding was recently challenged by Somberg and Salthouse (1982). The present study was conducted to investigate the possibility that age differences in dual-task performance are amplified by an increase in the difficulty of the constituent tasks, where difficulty was manipulated by varying the central, cognitive nature of the tasks (Experiment 1) or the degree of choice involved (Experiment 2). With the present tasks, strong evidence was found for an age-related decrement in divided attention performance. Contrary to our original expectations, however, it does not seem that division of attention presents some especial difficulty to older people. Rather, division of attention is one of several equivalent ways to increase overall task complexity. In turn, age differences are exaggerated as tasks are made more complex.     

S-R compatibility between response position and destination of apparent motion: evidence of the detection of affordances

In choice reaction time, stimuli and responses in some combinations (e.g., based on spatial arrangement) are faster than in other combinations. To test whether motion toward a position yields faster responses at that position, a computer-generated square in front of one hand appeared to move either toward that hand or toward the other hand. Compatible responses (e.g., motion toward left hand/left response) were faster than incompatible responses, even when that opposed traditional positional compatibility. In Experiment 2, subjects responded to the same stimuli but with both hands left, right, or on the body midline. Medial responses were the fastest, showing that destination, rather than mere relative position, was a critical variable. It was suggested that spatial compatibility effects are not unique to position but apply to a variety of task situations, describable by J.J. Gibson's theory of affordances, in which he claims that one perceives the actions (e.g., catching) permitted in a situation.     

Insight-oriented group psychotherapy of latency-age children in an acute care setting

Traditional approaches to group therapy with latency-age children have stressed activity and nonverbal therapeutic interventions. These approaches originated in the 1940s with Slavson's activity aroup therapy. A review of the literature of the past 25 years reveals that many clinicians have increasingly employed verbal techniques with latencyage groups. Most such reports describe groups for latency-age out-patients. In this paper, a verbal, interpretive technique for group therapy with latency-age inpatients is described. Clinical vignettes are included to illustrate this technique. Our experience suggests that such a technique can become an integral part of the inpatient treatment program for the latency-age child.