Helen Smith

Sep 1, 2024 | mdpi.com | Boon Chong Kwok |Helen Smith |Pui Wah Kong |Boon Chong

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Nov 29, 2023 | biorxiv.org | Helen Smith |Patrick Biggs |Nigel French |ADAM SMITH

AbstractLevels of a predictor variable that are absent when a classification tree is grown can not be subject to an explicit splitting rule. This is an issue if these absent levels then present in a new observation for prediction. To date, there remains no satisfactory solution for absent levels in random forest models. Unlike missing data, absent levels are fully observed and known. Ordinal encoding of predictors allows absent levels to be integrated and used for prediction.