A taxonomy of item response models

A number of models for categorical item response data have been proposed in recent years. The models appear to be quite different. However, they may usefully be organized as members of only three distinct classes, within which the models are distinguished only by assumptions and constraints on their parameters. “Difference models” are appropriate for ordered responses, “divide-by-total” models may be used for either ordered or nominal responses, and “left-side added” models are used for multiple-choice responses with guessing. The details of the taxonomy and the models are described in this paper. The present study was supported in part by two postdoctoral fellowships awarded to Lynne Steinberg: an Educational Testing Service Postdoctoral Fellowship at ETS, Princeton, NJ and an NIMH Individual National Research Service Award at Stanford University, Stanford, CA. Helpful comments by the editor and three anonymous reviewers are gratefully acknowledged.     

On the detectability of straight lines in visual noise: An extension of French’s paradigm into the millisecond domain

We report the results of a study that investigated the effects of four experimental parameters on the tachistoscopic detectability of dotted lines in a noisy background consisting of dynamic patterns of identical dots. Characteristics of the lines that were explored included dot spacing, dot numerosity, and line orientation. Dot spacing was shown to be the most powerful parameter in determining the masking effect: the closer the dots, the more easily the line was detected. Increasing the number of the dots was also effective in increasing the detectability of a line, but only up to a limit of five dots. The orientation of the line, on the other hand, did not alter its detectability. Increasing the density of the visual masking noise monotonically reduced the detectability of the line. These studies are an extension of French’s (1953, 1954) work, differing mainly in the fact that the stimulus material was presented tachistoscopically rather than in a mode that allowed prolonged (up to 5 sec) examination of the figures. Thus, they put the results in a domain in which physiological interpretations may be more critically evaluated. A comparison of the results suggests that essentially the same sorts of cognitive mechanisms are operating in the millisecond domain as in the longer exposures. This suggests that simple neurological models utilizing the concept of feature filters or detectors may be being prematurely applied to relatively complex perceptual processes.     

The role of observer attitudes in judgments of blame in cases of wife assault

This study examines the importance of observer characteristics in determining blame in cases of wife assault. Four independent variables (observer's attitudes toward sex roles, observer sex and age, and victim behavior) were assessed for their influence on the blaming judgments of 128 participants. Subjects completed a questionnaire that contained demographic items and six wife assault vignettes that varied in level of victim provocation (low or high). Questions about blame of the husband and wife followed each vignette. An attitudes toward women scale (AWS-B) was then administered. The main hypothesis, that subjects with traditional attitudes would blame the victim more and the perpetrator less for the assault than their egalitarian counterparts, was supported, as was the prediction of an interaction between provocation and AWS-B. The results are discussed in light of the role of observer attitudes in attribution models.     

Contextualizing social identity in considerations of what it means to be a nurse

This paper describes research which provide the context for a discussion of how social representations can circumscribe identity possibilities and render feasible certain groups evaluations. Specifically, a research approach is advocated in which Social Identity and Social Representation Theory are integrated within single complementary paradigm, (Breakwell, 1993). A brief but critical examination of both theoretical traditions is ofered as the backdrop to this. A case study is described as a means of illustrating the unique potential of the integrated paradigm to predict and explain the meaning of social identity and the evaluations it affords. An investigation is then described involving 178 nurses ranging from Trainee to Charge Nurse status. Nurses were invited to use Q-sorts to describe the meaning of their group membership. As predicted from having identified the types of social representation of nurses available, two diferent identity orientations emerged: a communal-interpersonal (Patient Centred) and instrumental-intergroup (Professional Distinctiveness). The communal-interpersonal identity orientation was most typical of the lower status trainee nurses and also female nurses. In turn, higher status nurses and also male nurses, articulated a primarily instrumental-intergroup identity orientation. The evaluations signalled by group membership were also predictable from the identity orientations exhibited.     

Parents, infants, and day-care teachers: Interrelations and implications for better child care

Many young children are reared today in both family and child-care settings. The relation that exists between these two settings has important implications for child care. Bronfenbrenner's (1979) ecological model is used as a way to view the interrelations among children, families, and child-care programs. Data from a study of infants in day care provide information on the time infants spend in family and day-care contexts, how parents and caregivers view children's behavior in these two settings, and rates of otitis media (ear infections) and other illnesses for these children. Results show that infants spend about twice as many hours per day awake with parents as in day care. Regarding child behaviors, parents and caregivers seem to have similar behaviors they like and dislike, but they each see particular children quite differently with respect to these behaviors. Finally, infants in this sample were diagnosed with illnesses 60% to 70% of the time. Findings are discussed in terms of the ecological model with particular attention given to relations between parents and caregivers.     

SPEECH PERCEPTION AS A TALKER-CONTINGENT PROCESS

Abstract— To determine how familiarity with a talker's voice affects perception of spoken words, we trained two groups of subjects to recognize a set of voices over a 9-day period One group then identified novel words produced by the same set of talkers at four signal-to-noise ratios Control subjects identified the same words produced by a different set of talkers The results showed that the ability to identify a talker's voice improved intelligibility of novel words produced by that talker The results suggest that speech perception may involve talker-contingent processes whereby perceptual learning of aspects of the vocal source facilitates the subsequent phonetic analysis of the acoustic signal     

ADULTS LISTEN SELECTIVELY; INFANTS DO NOT

Abstract— Infants' auditory detection thresholds are higher than adult thresh olds. Since adults listen selectively for an expected test tone frequency, and selective listening improves their detection performance, one hypothesis about why infant thresholds are high is that infants do not listen selectively. This hypothesis was tested by obtaining listening bands from adults and from 7- to 9-month-old infants. The results replicate earlier findings that adults listen selectively but indicate that infants do not. Lack of selective listening likely contributes to infants' high thresholds. Further, the finding that infants and adults have different listening strategies has implications for infants' auditory perception in general.