8.12 Imputation methods

Another approach to handling missing values is to impute or estimate them. Missing value imputation has a long history in statistics and has been thoroughly researched. Good places to start are Little and Rubin (2014), Van Buuren (2012) and Allison (2001). In essence, imputation uses information and relationships among the non-missing predictors to provide an estimate to fill in the missing value.

Imputation methods:

• KNN (K-Nearest Neighbors)
• Tree-based methods (bagging, missRanger)
• Linear methods