Essential independence and likelihood-based ability estimation for polytomous items

A definition ofessential independence is proposed for sequences of polytomous items. For items satisfying the reasonable assumption that the expected amount of credit awarded increases with examinee ability, we develop a theory ofessential unidimensionality which closely parallels that of Stout. Essentially unidimensional item sequences can be shown to have a unique (up to change-of-scale) dominant underlying trait, which can be consistently estimated by a monotone transformation of the sum of the item scores. In more general polytomous-response latent trait models (with or without ordered responses), anM-estimator based upon maximum likelihood may be shown to be consistent for under essentially unidimensional violations of local independence and a variety of monotonicity/identifiability conditions. A rigorous proof of this fact is given, and the standard error of the estimator is explored. These results suggest that ability estimation methods that rely on the summation form of the log likelihood under local independence should generally be robust under essential independence, but standard errors may vary greatly from what is usually expected, depending on the degree of departure from local independence. An index of departure from local independence is also proposed.This work was supported in part by Office of Naval Research Grant N00014-87-K-0277 and National Science Foundation Grant NSF-DMS-88-02556. The author is grateful to William F. Stout for many helpful comments, and to an anonymous reviewer for raising the questions addressed in section 2. A preliminary version of section 6 appeared in the author's Ph.D. thesis.     

An exploration of leadership in a medical mutual help organization

Studied 45 current leaders of local chapters of a medical mutual help organization. Cluster analysis of variables depicting routes to leadership produced six clusters: Health Professionals with a Mission, Connected Health Professionals, Career Leaders, Grass-roots Founders, Connected Grass-roots Leaders, and Obligated Veterans. These clusters differed on criterion measures of burnout, hardiness, and perceived obligation to continue as a leader, e.g., Connected Health Professionals and Career Leaders were less burned out, more hardy, and perceived less of an obligation to continue in the leadership role than Health Professionals with a Mission. In terms of leadership activities, Help Provision and Advocacy constituted less than one fifth of all activities but were rated as most rewarding. In contrast, the activities that made up the bulk of leaders' work--building membership, system maintenance, and organizational growth--were not rated as particularly rewarding. Results are discussed in the context of research directions and practice.     

Regression analyses as a tool for studying reading processes: Comment on Just and Carpenters eye fixation theory

Just and Carpenter (1980) presented a theory of reading based on eye fixations wherein their “psycholinguistic” variables accounted for 72% of the variance in word gaze durations. This comment raises some statistical and theoretical problems with their use of simultaneous regression analysis of gaze duration measures and with the resulting theory of reading. A major problem was the confounding of perceptual with psycholinguistic factors. New eye fixation data are presented to support these criticisms. Analysis of fixations within words revealed that most gaze duration variance was contributed by number of fixations rather than by fixation duration.     

A retrospective survey of students' views on a family therapy training programme

This paper describes the development of the training programme offered at the Family Institute in Cardiff and presents the results of a retrospective survey reflecting the 'consumers' views of the programme. Questionnaires were sent to all students who had trained at the Institute between 1972 and 1977, to elicit information about their views of the placement, as well as their post-qualifying experience, activities and interest in family therapy. A briefer preliminary report has been published earlier (Dowling and Seligman, 1980).     

The influence of labor market discrimination on locus of control

Prior research has established the existence of racial differences in locus of control as well as a relationship between labor market experience and locus of control. This study extends this line of inquiry by examining the relationship between labor market discrimination and subsequent change in locus of control. Drawing on a national probability sample (N = 2857) of young men, multiple regression analysis was used to estimate the effect of labor market discrimination (over a 2-year period) on subsequent locus of control. The results indicate that perceptions of employment discrimination influence the level of externality among blacks, over and above racial identification. Blacks who view themselves as victims of employment discrimination experience twice the increase in externality as blacks reporting no awareness of discrimination.     

Muscle relaxation training for fear reduction of patients with psychological problems: a review of controlled studies

Twenty-four studies of relaxation training for fear reduction of patients with psychological problems, which were published between 1960 and 1980, are reviewed. It is argued that only studies of the outcome of courses are relevant in considering the efficacy of therapy and concluded that such courses are capable of reducing autonomic arousal during training and during rest and stress following the course, capable of reducing behavioural avoidance, and capable of reducing subjective reports of disorder. This fear-reducing effect is less than that of exposure, and future research should examine the value of adding relaxation training to exposure.     

On comprehending idioms: Do children get the picture?

This study examines children's comprehension of idioms. First, third, and fifth grade children (6, 8, and 10 years old) and college adults were read short stories containing contextual information and a key terminal sentence. The contextual information biased either an idiomatic, a literal, or am ambiguous (neutral) interpretation of the terminal sentence. The terminal sentence contained either an idiom (“fix his wagon”) or a changed form (“repair his wagon”) of the idiom. These manipulations were used to determine the role of contextual information and the conventional forms of idioms in idiom comprehension. After each story, the subjects were asked to explain the terminal sentence and to answer a “yes-no” question about the action described in the story. The results showed that idiomatic explanations and interpretations occurred more frequently for the idiom than the changed forms, and that there were strong developmental increases in making idiomatic interpretations of both forms. The results are discussed in terms of two current models of idiom comprehension.     

Putting personal growth into an occupational psychology curriculum

This paper outlines an alternative approach to curriculum design in higher education focusing in particular on the introduction of personal growth into the programme, and on facilitating the selection by students of the optimal choice of options. It is argued that models of curriculum design need to take cognizance of at least four interested parties; and that in the resolutions of their divergent interests, curriculum designers must make clear their most potent values, as well as their theories and assumptions about the nature of learning. A brief outline follows of two courses based upon these propositions. Finally, evaluations by both trainers and students involved in these courses are presented.