Press "Enter" to skip to content

Handling Definitional Changes In Predictive Variables

Vincent Granville explains how you can blend two different definitions of a variable of interest together:

The reasons why scores can become meaningless over time is because data evolves. New features (variables) are added that were not available before, the definition of a metric is suddenly changed (for instance, the way income is measured) resulting in new data not compatible with prior data, and faulty scores. Also, when external data is gathered across multiple sources, each source may compute it differently, resulting in incompatibilities: for instance, when comparing individual credit scores from two people that are costumers at two different banks, each bank computes base metrics (income, recency, net worth, and so on) used to build the score, in a different way. Sometimes the issue is caused by missing data, especially when users with missing data are very different from those with full data attached to them.

Click through for a description of the approach and links showing how it works in practice.