Modeling typical performance measures

In the educational, employment, and clinical context, attitude and personality inventories are used to measure typical performance traits. Statistical models are applied to obtain latent trait estimates. Often the same statistical models as the models used in maximum performance measurement are applied to typical performance measures. However, different models might be better applicable to describe these typical performance measures. In this dissertation the modeling of two systematic features in the typical performance domain is discussed; 1. the factor structure of typical performance measures, and 2.response processes to typical performance measures.\ud In the first part of the dissertation complex multidimensional models (e.g. bifactor model, non-hierarchical multidimensional model, second-order model) are investigated to describe the factor structure of both a personality inventory and an attitude inventory. In the second part of this dissertation the applicability of different response models, dominance IRT models and unfolding IRT models, to describe the response processes on two personality inventories is compared. In the next chapters an already existing unfolding IRT model, the generalized graded unfolding model (GGUM) is compared to three newly developed alternatives, the collapsed generalized partial credit model (CGPCM), the collapsed graded response model (CGRM) and the quadratic logistic regression model (QLOG) and the statistical fit of the models is investigated. Both person fit (constancy of theta statistic and tendency to agree statistic) and item fit (Differential item functioning and shape of item characteristic curve statistic) are investigated by fit statistics that are developed based on the Lagrange Multiplier (LM) test.\ud In general, it was found that it is important to not simply apply models that are used in maximum performance measurement to typical performance measurement. To investigate the dimensionality structure it is important to take both general and specific factors into account. Furthermore it is reasonable to expect that responses to typical performance measures follow an ideal-point response process. Four unfolding IRT models and methods to assess the statistical fit of the models were introduced

On the dimensionality of the Dispositional Hope Scale

The Dispositional Hope Scale (DHS; C. R. Snyder et al., 1991) consists of two subsets of items measuring Agency and Pathways. ne authors used bifactor analysis to evaluate the dimensionality structure of the scale. Data from 676 persons (295 psychiatric patients, 112 delinquents, and 269 students) were analyzed. The authors conclude that although the Pathway items seem to explain some additional variance when the Hope scale variance is partionalized out, the DHS allows unidimensional measurement

Gemiste dosering: carbamazepine bij epilepsie / orale anti-diabetesmiddelen

Deze artikelen maken deel uit van een serie artikelen over "vergeten dosering" in het Pharmaceutisch Weekblad. De wetenschapswinkel geneesmiddelen heeft samen met de Stichting Health Base onderzoek gedaan naar het effect van een vergeten dosering. Patienten en apothekers vinden het vaak lastig in te schatten wat je moet doen als je een tablet vergeten bent: overslaan, alsnog innemen, later innemen? Studenten farmacie hebben op basis van enkele veel gebruikte of lastige geneesmiddelen (bij epilepsie, diabetes, astma) uitgezocht wat er nu gebeurt als je een tablet vergeet en hoe je patient kan adviseren te handelen. De artikelen serie -geschreven in samenwerking met praktijkapothekers- omvat zes afleveringen: - Algemene overwegingen en tips bij vergeten van een dosering (met dank aan Jurgen Kwik en Arjan Groote) - Carbamazepine bij epilepsie (met dank aan Leander Wemmenhove en Maria Franken) - Orale anti-diabetes middelen (met dank aan Anke Tulp) - Methotrexaat voor verschillende aandoeningen - Statines tegen te hoog cholsterol - NSAID's bij pijn