Dichotomous decisions based on dichotomously scored items: a case study

In a course in elementary statistics for psychology students using criterion-referenced achievement tests, the total test score, based on dichotomously scored items, was used for classifying students into those who passed and those who failed. The score on a test is considered as depending on a latent variable; it is assumed that the students can be dichotomized into the categories "mastery" (with scores on the latent variable above a cutting score), and "no mastery" (with scores below the cutting score on the latent variable). Two problems are considered: (a) How many students are classified incorrectly? Using the binomial error model a procedure is described for computing the classification proportions: p(mastery, passed), p(mastery, failed), p(no mastery, passed), and p(no mastery, failed), (b) What is the optimal cutting score on a test? Using a loss function a procedure for computing the optimal curring score is described

The concept of quality of life in dementia in the different stages of the disease

In order to conceptually define quality of life (QOL) in dementia, the literature on QOL in the elderly population, in chronic disease and in dementia was studied. Dementia is a progressive, age-related, chronic condition and to avoid omissions within the dementia-specific concept of QOL, a broad orientation was the preferred approach in this literature study. Adaptation is a major outcome in studies investigating interventions aimed at improving QOL in chronic conditions, but to date, it has not been used in the definition of QOL. It is argued that adaptation is an important indication of QOL in people with chronic diseases and therefore also in dementia. Some crucial issues in assessing dementia-related QOL that are relevant to clarify the continuing debate on whether QOL, particularly in dementia, can be measured at all, are discussed. Then the following conceptual definition is offered: dementia-specific QOL is the multidimensional evaluation of the person-environment system of the individual, in terms of adaptation to the perceived consequences of the dementi

Syndrome dimensions and the Child Behavior Checklist and the Teacher Report Form: A critical empirical evaluation

The construct representation of the cross-informant model of the Child Behavior Checklist (CBCL) and the Teacher Report Form (TRF) was evaluated using confirmatory factor analysis. Samples were collected in seven different countries. The results are based on 13,226 parent ratings and 8893 teacher ratings. The adequacy of fit for the cross-informant model was established on the basis of three approaches: conventional rules of fit, simulation, and comparison with other models. The results indicated that the cross-informant model fits these data poorly. These results were consistent across countries, informants, and both clinical and population samples. Since inadequate empirical support for the cross-informant syndromes and their differentiation was found, the construct validity of these syndrome dimensions is questioned