In prospective studies, disease rates during follow-up are typically analyzed with respect to the values of factors measured during an initial baseline survey. However, because of "regression dilution," this generally tends to underestimate the real associations of disease rates with the "usual" levels of such risk factors during some particular exposure period. The "regression dilution ratio" ...

The observational data relating salt and blood pressure (excluding INTERSALT) are reviewed. Important methodological difficulties and biases are inherent to both across- and within-population studies and confuse their interpretation. Across-population studies are positive but rely on data drawn from the international literature based on a variety of unstandardized field methods; they are prone ...

Self-Esteem and Earnings Recent research in economics suggests a positive association between self-esteem and earnings. A major problem in this literature is that from simple cross-sectional wage regressions it is not possible to conclude that self-esteem has a causal impact on earnings. While classical measurement error leads to an attenuation bias, reverse causality and omitted variable are l...

Test bias, in contrast to test fairness, is best conceptualized in validity terms amenable to statistical analysis. Evidence of predictive validity may be most salient in many situations. Evaluation of predictive bias is generally operationalized via linear regression. Potthoff (1978) provided an efficient and parsimonious regression bias procedure that allows both simultaneous and separate tes...

The domain state model for exchange bias is used for an investigation of recent experiments where the magnitude and direction of the exchange bias was controlled by He ion irradiation of an FeNi/FeMn sample. The defects in the sample which result from the irradiation are modeled as diluting the antiferromagnet ~AFM! after the initial cooling procedure. This late dilution, carried out in presenc...

The exchange bias coupling at ferromagnetic/antiferromagnetic interfaces in epitaxially grown Co/CoO layers can intentionally be increased by a factor of up to 3 if the antiferromagnetic CoO layer is diluted by nonmagnetic defects in its volume part away from the interface. Monte Carlo simulations of a simple model of a ferromagnetic layer on a diluted antiferromagnet show exchange bias and exp...