Normalization rules for item response models: Simulation results

ABSTRACT

This research examines the statistical methodology that is used to estimate the parameters in item response models. An integral part of an item response model is the normalization rule that is used to identify the distributional parameters. The main result shown here is that only Verhelst–Glas normalizations that arbitrarily set one difficulty and one dispersion parameter to unity are consistent with the basic assumptions underlying the two-parameter logistic model. Failure to employ this type of normalization will lead to scores that depend on the item composition of the test and differential item difficulty (DIF) will compromise the validity of the estimated ability scores when different groups are being compared. It is also shown that some of the tests for DIF fail when the data are generated by an IRT model with a random effect. Most of the results are based on simulations of a four item model. Because the data generation mechanism is known, it is possible to determine the effect on ability scores and parameter estimates when different normalizations or different distribution parameter values are used.     

Determinants of workplace health program participation among non,low, and incentive-achieving participants

The authors used a cross-sectional survey and zero-inflated ordered probit modeling to investigate individual psychosocial-, interpersonal-, organizational-, and community-level determinants distinguishing nonparticipants, low-level participants, and incentive-achieving participants in a single, university-based worksite health program (WHP) that uses insurance premium reductions to incentivize participation. Results from 319 employees suggested two nonparticipant groups. Persons without employer-sponsored insurance, those with negative participation perceptions, and men were more likely to be “never” participants; those who had never met the incentive were potential future participants. Increased confidence was related to incentive achievement; stress was associated with low participation. No interpersonal, organizational, or community factors were significant. When structuring incentives, WHPs should consider determinants of participation, vis-à-vis the incentive.     

The role of antenatal and postnatal maternal bonding in infant development: A systematic review and meta‐analysis

The purpose of this study was to systematically review the empirical literature on maternal bonding and associations with infant physical, psychological, and social development. Nineteen articles met inclusion criteria and were included in a qualitative synthesis (79 effect sizes); 15 articles were suitable for aggregation in a series of 14 meta‐analyses (51 effect sizes). All mean effects were in the expected direction, with higher maternal bonding contributing to infant developmental outcomes, including higher attachment quality (r = .35) and parent‐reported lower colic rating (r = .22), easier temperament (r = .19), and positive infant mood (r = .27). Consistent with theoretical explanatory models, the review provides support for the hypothesis that maternal bonding plays a role in fostering more optimal infant development. The review also identifies a paucity of empirical work on this topic and provides directions for future research.     

Scholastic ability vs family background in educational success: evidence from Danish sample survey data

This research examines the role of scholastic ability and family background variables in the determination of educational attainment in Denmark. A categorical representation of the highest level of education attained by the individual is the dependent variable. It is analyzed by procedures that take account of the presence of unobservable factors. Parent’s education and occupation, along with an indicator of scholastic ability which is represented by a set of aptitude tests, explain a small but significant portion of the variation in their children’s educational success. Women are shown to respond differently to their environments than men, and including these test scores does not remove the need to deal with unmeasured attributes. On the basis of the available data, family background variables as a group contribute more to the explained variation in the data than the test scores. Finally, credit constraints do not appear to be a factor in educational attainments.

Doctoral Theses 1954-1996

The present article centres on a group of Indonesians and Australians who are members of a gamelan ensemble based at the Consulate of the Republic of Indonesia in Perth, Western Australia. By examining why Australians and Indonesians choose to participate in this musical community, the article investigates how these individuals negotiate and construct musical identities to give local meaning to gamelan in the West Australian context.     

Returns to scale to family size - who gains from high fertility?

Summary In this paper the hypothesis put forward by J. C. Caldwell in a number of recent articles, including one in this journal is tested, that there are social and economic increasing returns to scale to family size. Using two village samples of household data collected in Bangladesh in 1977, it is shown that there is a statistically significant inverse correlation between adjusted consumption of rice per head and family size. This result holds true when age and size of landholding are taken into account. From this, it is concluded that the hypothesis is not empirically supported by the data from Bangladesh. This result is partially explained by the extreme poverty of the region and the fact that women are exploited in Bangladesh society.