Missing data: our view of the state of the art.
Statistical procedures for missing data have vastly improved, yet misconception and unsound practice still abound. The authors frame the missing-data problem, review methods, offer advice, and raise issues that remain unresolved. They clear up common misunderstandings regarding the missing at random (MAR) concept. They summarize the evidence against older procedures and, with few exceptions, discourage their use. They present, in both technical and practical language, 2 general approaches that come highly recommended: maximum likelihood (ML) and Bayesian multiple imputation (MI). Newer developments are discussed, including some for dealing with missing data that are not MAR. Although not yet in the mainstream, these procedures may eventually extend the ML and MI methods that currently represent the state of the art.
Schafer
Joseph L
JL
Department of Statistics and the Methodology Center, Pennsylvania State University, University Park 16802, USA. jls@stat.psu.edu
Graham
John W
JW
D019992:Databases as Topic; D006801:Humans; D008962:Models, Theoretical; D012106:Research / Q000592:standards*; D012984:Software