The National Assessment of Educational Progress (NAEP) uses latent trait item response models to summarize performance of students on assessments of educational proficiency in different subject areas ...

The Centre for Multilevel Modelling has a long-standing interest in developing methods and software to aid researchers in handling missing data. As discussed below, we have developed functionality in ...

Missing data are a frequently encountered problem in epidemiologic and clinical research.1, 2 One approach is to include in the analysis only those participants without missing observations (complete ...

Single Imputation Averages or Medians: With single imputation, a particular algorithm or technique is used to produce a single estimate for each missing value. Assuming randomly missing data, the ...

In reconstructing exposure histories needed to calculate cumulative exposures, gaps often occur. Our investigation was motivated by case-control studies of residential radon exposure and lung cancer, ...

Previous work (Carpenter and Goldstein 2004: Multilevel Modelling Newsletter 16 (2) (PDF, 298kB)) implements procedures that are based on methodological extensions that allow multivariate mixtures of ...