Continuous and discrete latent structure models for item response data

Relations are examined between latent trait and latent class models for item response data. Conditions are given for the two-latent class and two-parameter normal ogive models to agree, and relations between their item parameters are presented. Generalizationss are then made to continuous models with more than one latent trait and discrete models with more than two latent classes, and methods are presented for relating latent class models to factor models for dichotomized variables. Results are illustrated using data from the Law School Admission Test, previously analyzed by several authors.     

The more you have,the more you want? Higher social class predicts a greater desire for wealth and status

Traditional theories have focused on the intentions of lower-class individuals to climb on the social ladder, yet they have paid relatively little attention to the motivations of upper-class individuals to ascend even higher. Addressing this issue, Studies 1 and 2 provided cross-national evidence that higher social class is associated with a greater desire for wealth and status. Moreover, by manipulating perceived social class, Studies 3 and 5 experimentally confirmed that compared to people in the lower-class group, those in the upper-class group express a stronger desire for wealth and status. Furthermore, in line with self-categorization theory predictions, Studies 3–5 showed that upper-class individuals tend to see and use wealth and status as important attributes in defining and categorizing self, and this tendency explains the effect of social class on desire for wealth and status. Together, our findings demonstrate a “having more—wanting more” relationship, and its consequences are further discussed.     

Hotep's Story: Exploring the Wounds of Health Vulnerability in the US

A wide variety of forms of domination hasresulted in a highly heterogeneous health riskcategory, ``the vulnerable.' The study of healthinequities sheds light on forces thatgenerate, sustain, and alter vulnerabilities toillness, injury, suffering and death. Thispaper analyzes the case of a high-risk teenfrom a Boston ghetto that illuminatesintersections between ``race' and class in theconstruction of vulnerability in the US.Exploration of his ``wounds' helps specify howlarge-scale social and cultural forces becomeembodied as individual experience of disparatehealth risk. The case demonstrates that healthinequities would not occur if resources –employment, income, wealth, education, housing,profiling in the legal system, and health care– were more justly managed in keeping withstandards outlined in the Universal Declarationof Human Rights. Professional responses to the``wounds of vulnerability' may reveal importantaspects of who we are and what our work asscholars, practitioners, and advocates mustbecome.     

Semantic similarity and grammatical class in naming actions

Italian speakers were asked to name pictures of actions (e.g. "bere", to drink). Pictures were presented at the same time as distracter words that were semantically related or unrelated to the picture names, and were of the same or different grammatical class (verbs or nouns). Half of the participants named the actions as verbs in citation form, the other half as verbs inflected for third person singular or plural. We found a reliable semantic interference effect. Crucially, we also observed a significant interaction between naming context and grammatical class: naming latencies were slower for verb distracters in the inflected form condition, but not in the citation form condition. The results are taken to provide evidence for the separability of semantics and grammatical class.     

A person-fit index for polytomous rasch models,latent class models,and their mixture generalizations

A normally distributed person-fit index is proposed for detecting aberrant response patterns in latent class models and mixture distribution IRT models for dichotomous and polytomous data.This article extends previous work on the null distribution of person-fit indices for the dichotomous Rasch model to a number of models for categorical data. A comparison of two different approaches to handle the skewness of the person-fit index distribution is included.Major parts of this paper were written while the first author worked at the Institute for Science Education, Kiel, Germany. Any opinions expressed in this paper are those of the authors and not necessarily of Educational Testing Service. The results presented in this paper were improved by valuable comments from J. Rost, K. Yamamoto, N.D. Verhelst, E. Bedrick and two anonymous reviewers.     

Conservative Theories of Classical Truth

Some axiomatic theories of truth and related subsystems of second-order arithmetic are surveyed and shown to be conservative over their respective base theory. In particular, it is shown by purely finitistically means that the theory PA ÷ "there is a satisfaction class" and the theory FS of [2] are conservative over PA.     

A latent class analysis of positive psychosis symptoms based on the British Psychiatric Morbidity Survey

This study aimed to describe the distribution of positive psychosis symptoms in a large scale, population-based sample. Data from the British Psychiatric Morbidity Survey was used to examine homogeneous sub-types of participants based on their responses to the five probe items of the Psychosis Screening Questionnaire. Latent class analysis was used to identify the underlying class structure of psychosis. Four classes of psychosis were identified. Associations between the latent classes and the demographic risk factors, clinical variables and reports of traumatic experiences showed significantly higher risks for the psychosis class, the paranoid class, and the intermediate class compared to the normative class. Four classes that appeared to represent an underlying continuum could best explain psychosis symptom expression at the population level.