In contrast to randomized experiments, the estimation of unbiased treatment effects from observational data requires an analysis that conditions on all confounding covariates. Conditioning on covariates can be done via standard parametric regression techniques or nonparametric matching like propensity score (PS) matching. The regression or…

The Delphi method is a means of structuring group communication process so that a group of experts can gather information or forecast future problems effectively. A primary objective of a Delphi study is to obtain consensual and consistent opinions from a group of experts in two or more successive rounds on a given research subject. Consensus and…

The accuracy of the large sample standard error of weighted kappa appropriate to the non-null case was studied by computer simulation for the hypothesis that two independently derived estimates of weighted kappa are equal, and for setting confidence limits around a single value of weighted kappa. (Author/CTM)