Title
A new variable importance measure for random forests with missing data
Abstract
Random forests are widely used in many research fields for prediction and interpretation purposes. Their popularity is rooted in several appealing characteristics, such as their ability to deal with high dimensional data, complex interactions and correlations between variables. Another important feature is that random forests provide variable importance measures that can be used to identify the most important predictor variables. Though there are alternatives like complete case analysis and imputation, existing methods for the computation of such measures cannot be applied straightforward when the data contains missing values. This paper presents a solution to this pitfall by introducing a new variable importance measure that is applicable to any kind of data--whether it does or does not contain missing values. An extensive simulation study shows that the new measure meets sensible requirements and shows good variable ranking properties. An application to two real data sets also indicates that the new approach may provide a more sensible variable ranking than the widespread complete case analysis. It takes the occurrence of missing values into account which makes results also differ from those obtained under multiple imputation.
Year
DOI
Venue
2014
10.1007/s11222-012-9349-1
Statistics and Computing
Keywords
DocType
Volume
Variable importance measures,Permutation importance,Random forests,Missing values,Missing data
Journal
24
Issue
ISSN
Citations 
1
0960-3174
18
PageRank 
References 
Authors
0.81
18
4
Name
Order
Citations
PageRank
A. Hapfelmeier1775.52
Torsten Hothorn246337.24
Kurt Ulm3262.36
Carolin Strobl41226.31