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Regression targets where extrapolation may be needed. Decision tree methods cannot extrapolate, the predictions are have to be a mean of a subgroup of the data.
by dcl 3y ago
Regression targets where extrapolation may be needed. Decision tree methods cannot extrapolate, the predictions are have to be a mean of a subgroup of the data.
Consider: Predicting how much a customer might pay by end of month, with information we have at the start of the month.
In this example, if a customer had a record $10m of open invoices due by EoM and the largest payment amount received in prior months of $5m, the decision tree cannot possibly predict the payment amount will be ~$10m, even when the best feature indicates the payment will be $10m.
There are some hacks/techniques which can maybe reduce this issue, but they don't always work.
- melondonkey 3y agoWhat? Can you explain the mechanism than a NN can “extrapolate” an invoice where a tree model couldn’t? This is all just how the modeler builds the features. Also all models are a “mean of the subgroup of the data.” The prediction is by definition the conditional mean as a function of the input values.