Robust estimation of ability in the Rasch model

Estimating ability parameters in latent trait models in general, and in the Rasch model in particular is almost always hampered by noise in the data. This noise can be caused by guessing, inattention to easy questions, and other factors which are unrelated to ability. In this study several alternative formulations which attempt to deal with these problems without a reparameterization are tested through a Monte Carlo simulation. It was found that although no one of the tested schemes is uniformly superior to all others, a modified jackknife stood out as the best one in general, it was also super efficient (more efficient than the asymptotically optimal estimator) for tests with forty or fewer items. It is proposed that this sort of jackknifing scheme for estimating ability be considered for practical work.This research was funded through a grant from the Law Enforcement Assistance Administration (78-NI-AX-0047) to the Bureau of Social Science Research, Howard Wainer, Principal Investigator. We would like to thank Ronald Mead, Anne Morgan and James Ramsay for kind, generous, and invaluable help at various stages of the project.     

Depression in children: Parent,teacher, and child perspectives

Depressed and nondepressed children were found to differ in the types of behavior problems manifested at home and at school. Children rated as depressed by their parents on the Personality Inventory for Children evidenced significantly more conduct problems, anxiety, impulsive hyperactivity, learning problems, psychosomatic problems, perfectionism, and muscular tension at home than children rated as nondepressed. Depressed children were rated by their teachers as displaying more inattentionpassivity than nondepressed children. A significant but modest relationship was found between parent report and child selfreport of the child's depression. Depressed children attributed positive events to external causes and negative events to internal causes significantly more than did nondepressed children. The specificity of these results to depression was also examined;the particular features of childhood depression are compared to the features of adult depression. The investigators would like to thank Jim McFerren and Ralph Zalazar for their work as research assistants and David Watson for his help with the statistical analyses. The helpful comments of Eric Klinger and Auke Tellegen are gratefully acknowledged. The cooperation of Dr. Loren Benson, director of personnel services of the Hopkins School District #274; Mr. Edward Ryshavy, principal of Glen Lake Elementary School; and the teachers of that school is greatly appreciated.     

A CPI comparison of engineers and managers

Seventy-one male employees of three high-technology content product industries in northern Utah were divided into three contrast groups: engineers, engineering-trained managers, and non-engineering-trained managers. The California Psychological Inventory was administered and multivariate analysis of variance performed on seven preselected CPI scales. Results revealed that nonengineering managers scored significantly higher than engineers on scales Dominance, Capacity for Status, Social Presence, and approached significance on Sociability. Engineering-managers also scored significantly higher than engineers on Dominance, and significantly higher than other managers on Psychological Mindedness. A multivariate main-effect significant p < .001 to predict group membership was found. Engineering-managers share with other managers a confident, persuasive, and aggressive self-presentation combined with a preference for leadership roles. Their elevation on Psychological Mindedness, however, suggests a more pragmatic analytical and less intuitive approach to management situations.     

Effective random seeding of random number generators

To obtain different sequences of values from a random number generating algorithm, we must start with different seed values or discard a variable number of initial samples. For maximum independence among sequences, differences must include the lowest order seed bits, and some generators require one to wait many samples for differences to propagate to the significant bits. While it is straightforward to generate two statistically independent sequences, it is surprisingly difficult to generate three or more such sequences.     

Attention to important versus trivial tasks and salience of fatigue-related symptoms for coronary prone individuals

The present study tested the hypothesis that individuals with the Type A coronary prone behavior pattern focus their attention more on important tasks, and less on trivial tasks than do Type B's. The study used a paradigm in which some subjects worked on math problems (important task) and rated intervening mood items (trivial task), whereas others rated mood items they were to memorize (important task) and worked on intervening math problems (trivial task). All subjects were later tested on recall of mood items. Results indicated that Type A's performed better on math problems and recalled more fatigue-related mood items when the task was important than when it was trivial; for Type B subjects, there was no difference in the number of math problems solved correctly or number of mood items recalled between important and trivial task conditions. Moreover, Type A's reported greater fatigue when mood recall was the important task than when math was the important task, whereas fatigue ratings of Type B's did not differ across these conditions. The findings suggest that Type A's suppress their attention to fatigue-related symptoms only when symptoms are not the objects of focus.     

Selective involvement of the auditory-verbal modality in an acquired communication disorder: Benefit from sign language therapy

A 39-year-old female suffered bitemporal infarctions and exhibited an unusual behavioral syndrome of muteness and impaired auditory comprehension, with milder aphasic deficits in reading and writing. The anatomic basis of this modality-selective communication disorder appeared to involve both peripheral perceptual and motor as well as “central” language mechanisms. The patient's ability to communicate was greatly aided by instruction in Amerind and Ameslan Sign Language, in which she learned more than 100 signs. Patients whose acquired language deficits spare modalities of input or output may be ideal candidates for sign language therapy.     

Right-left confusion in the adult: A verbal labeling effect

Directional judgments are typically slower when relative location is described by the words “east” and “west” or “right” and “left” than when described by the words “north” and “south” or “up” and “down.” A series of experiments are reported that disentangle verbal from perceptual encoding explanations for right-left difficulty. Overall, our results support a verbal encoding explanation for right-left confusion in the adult. Experiments 1-3 demonstrate that in a response-differentiation task, it is response to the labels “north,” “east,” “south,” and “west” that is responsible for right-left confusion. In addition, Experiments 4-6 demonstrate that right-left difficulty in a mirror image discrimination task is contingent on the use of directional labels. (The data also suggest that it may be more difficult to deal with “up,” “down,” “left,” and “right” than with “north,” “south,” “east,” and “west”) The data are interpreted as inconsistent with a bilateral symmetry explanation for right-left confusion.     

The effect of phonemic processing on the retention of graphemic representations for words and nonwords

The three experiments reported in this study were each conducted in two phases. The first phase of Experiment 1 involved a same-different comparison task requiring “same” responses for both mixed-case (e.g., MAIN main) and pure-case (e.g., near near) pairs. This was followed by Phase 2, a surprise recognition test in which a graphemic effect on word retention was indicated by the superior recognition accuracy obtained for pure-case compared with mixed-case pairs. The first phases of Experiments 2 and 3 involved pronounceability and imageability judgment tasks, respectively. Graphemic retention was assessed by contrasting recognition accuracy for letter strings presented, during Phase 2, in their original Phase 1 case, with letter strings presented, during Phase 2, in. a graphemically dissimilar new case. The experiments provided evidence that there was minimal retention of the graphemic representations from which the phonemic representations of words are generated and, further, that the locus of this effect is probably postlexical. Nonwords were recognized more accurately than words in all three experiments. The latter result was attributed to differences between nonwords and words in both graphemic retention and semantic distinctiveness.     

Perception of movement in American Sign Language: Effects of linguistic structure and linguistic experience

In order to reveal the psychological representation of movement from American Sign Language (ASL), deaf native signers and hearing subjects unfamiliar with sign were asked to make triadic comparisons of movements that had been isolated from lexical and from grammatically inflected signs. An analysis of the similarity judgments revealed a small set of physically specifiable dimensions that accounted for most of the variance. The dimensions underlying the perception of lexical movement were in general different from those underlying inflectional movement, for both groups of subjects. Most strikingly, deaf and hearing subjects significantly differed in their patterns of dimensional salience for movements, both at the lexical and at the inflectional levels. Linguistically relevant dimensions were of increased salience to native signers. The difference in perception of linguistic movement by native signers and by naive observers demonstrates that modification of natural perceptual categories after language acquisition is not bound to a particular transmission modality, but rather can be a more general consequence of acquiring a formal linguistic system.