Design consistent random forest models for data collected from a complex sample
Articles and reports: 12-001-X202400200015Description: Random forest models, which are the result of averaging the estimated values from a large number of tree models, represent a useful and flexible tool for modeling the data nonparametrically to provide accurately predicted values. There are many potential applications for these types of models when dealing with survey data. However, survey data is usually collected using an informative sample design, so it is necessary to have an algorithm for creating random forest models that account for this design during model estimation. The tree models used in the forest are typically obtained by estimating tree models on bootstrapped samples of the original data. Since the models depend on the observed data and the values observed in the sample depend on the informative sample design, the usual method for estimation is likely to lead to a biased random forest model when applied to survey data. In this article, we provide an algorithm and a set of conditions that produce consistent random forest models under an informative sample design and compare this method to the usual random forest modeling method. We show that ignoring the design can lead to biased model estimates.
Issue Number: 2024002Author(s): Toth, Daniell; McConville, Kelly S.Main Product:Survey Methodology