Based on a classical true score theory (classical test theory, CTT) equation, indicating that as the observed correlation between two tests increases, the reliability of the difference scores decreases, researchers have concluded that difference scores are unreliable. But CTT shows that the reliabilities of the two tests and the true correlation between them influence the observed correlation a...

Environmental epidemiologic studies are often hierarchical in nature if they estimate individuals’ personal exposures using ambient metrics. Local samples are indirect surrogate measures of true local pollutant concentrations which estimate true personal exposures. These ambient metrics include classical-type nondifferential measurement error. The authors simulated subjects’ true exposures and ...

Environmental epidemiologic studies are often hierarchical in nature if they estimate individuals' personal exposures using ambient metrics. Local samples are indirect surrogate measures of true local pollutant concentrations which estimate true personal exposures. These ambient metrics include classical-type nondifferential measurement error. The authors simulated subjects' true exposures and ...

iv 1 Regressed-score Estimates 1 2 Reliability 1 2.1 Correlational-based Definitions of Reliability . . . . . . . . . . . 2 2.2 Variance-ratio Expressions for Reliability . . . . . . . . . . . . . 2 3 Covariances Involving Error 3 3.1 Zero Covariance for True and Error Scores in CTT . . . . . . . . 3 3.2 Zero Expectation for Errors for Persons in CTT . . . . . . . . . . 4 4 Concluding Comments 4

the classical test theory (ctt) and item response theory (irt) are widely used in construction and analysis of exams and questionnaires. because of the various shortcomings of ctt, irt has been designed. even though irt has overcome most of the limitations of ctt and has made computer adaptive testing possible, it is still important to point out that not enough reasons exist to totally discard ...

– We introduce three measures which quantify the degree to which quantum systems possess the robustness exhibited by classical systems when subjected to continuous observation. Using these we show that for a fixed environmental interaction the level of robustness depends on the measurement strategy, or unravelling, and that no single strategy is maximally robust in all ways. When describing the...

In order to be useful for their intended purposes, outcome measures (rating scales and questionnaires) must provide information that allows valid inferences and decisions to be made. Basic classical test theory is still widely used in peer-reviewed, indexed journals for validating these tools. Classical test theory methods mainly focus on an instrument's total score, whichis simply asserted as ...