A review of issues and controversy surrounding F-ratio denominator degrees of freedom (DDF) in linear mixed models. The presentation will look at the history of denominator degrees of freedom as well survey their use in various statistical packages.

This presentation will show how to use of the new margins command, introduced in Stata 11, to explore interactions in regression and analysis of variance. The talk will cover three types of interactions: 1) categorical by categorical, 2) categorical by continuous, and 3) continuous by...

This presentation will give an overview of the three main approaches to analyzing repeated measures analysis of variance: 1) Multivariate models, 2) traditional anova models, and 3) linear mixed models along with discussion of the advantages and disadvantages of each. The presentation includes...

Three approaches to understanding 3-way anova interactions will be presented: 1) a conceptual approach, 2) an anova approach and 3) a regression approach using dummy coding. The three approaches are illustrated through the use of a synthetic dataset with a significant 3-way interaction.

I present the new Stata 12 command, mi impute chained, to perform multivariate imputation using chained equations (ICE), also known as sequential regression imputation. ICE is a flexible imputation technique for imputing various types of data. The variable-by-variable specification of ICE allows...

Splines, including polynomials, are traditionally used to model nonlinear relationships involving continuous predictors. However, when they are included in linear models (or generalized linear models), the estimated parameters for polynomials are not easy for nonmathematicians to understand, and...

We will discuss SEM (structural equation modeling), not from the perspective of the models for which it is most often used--measurement models, confirmatory factor analysis, and the like--but from the perspective of how it can extend other estimators. From a wide range of choices, we will focus...

One of the aims of a phase I trial in oncology is to find the maximum tolerated dose. A set of doses is administered to participants starting from the lowest dose in increasing steps. To do this safely, the toxicity of each dose is assessed, and a decision is made about whether to proceed with...

It is well-known that the dummy variable estimator for the fixed-effects ordered logit model is inconsistent when T, the dimension of the panel, is fixed. This talk will review a range of alternative fixed-effects ordered logit estimators that are based on Chamberlain's fixed-effects estimator...

This talk presents a simple graphical device for visualization of patterns of income mobility. The device uses color palettes to picture information contained in transition matrices created from a fine partition of the marginal distributions. The talk explains how these graphs can be constructed...