## Variable Utility is not Intrinsic

There is much ado about variable selection or variable utility valuation in supervised machine learning. In this note we will try to disarm some possibly common fallacies, and to set reasonable expectations about how variable valuation can work. Introduction In general variable valuation is estimating the utility that a column […]

## Don’t Feel Guilty About Selecting Variables

We have an exciting new article to share: Don’t Feel Guilty About Selecting Variables. If you are at all interested in the probabilistic justification of important data science techniques, such as variable selection or pruning, this should be an informative and fun read. “Data Science” is often criticized with the […]

## R Tip: Use the vtreat Package For Data Preparation

If you are working with predictive modeling or machine learning in R this is the R tip that is going to save you the most time and deliver the biggest improvement in your results. R Tip: Use the vtreat package for data preparation in predictive analytics and machine learning projects. […]

## A Theory of Nested Cross Simulation

[Reader’s Note. Some of our articles are applied and some of our articles are more theoretical. The following article is more theoretical, and requires fairly formal notation to even work through. However, it should be of interest as it touches on some of the fine points of cross-validation that are […]

## Variables can synergize, even in a linear model

Introduction Suppose we have the task of predicting an outcome y given a number of variables v1,..,vk. We often want to “prune variables” or build models with fewer than all the variables. This can be to speed up modeling, decrease the cost of producing future data, improve robustness, improve explain-ability, […]

## Variable pruning is NP hard

I am working on some practical articles on variable selection, especially in the context of step-wise linear regression and logistic regression. One thing I noticed while preparing some examples is that summaries such as model quality (especially out of sample quality) and variable significances are not quite as simple as […]

## vtreat version 0.5.26 released on CRAN

Win-Vector LLC, Nina Zumel and I are pleased to announce that ‘vtreat’ version 0.5.26 has been released on CRAN. ‘vtreat’ is a data.frame processor/conditioner that prepares real-world data for predictive modeling in a statistically sound manner. (from the package documentation) ‘vtreat’ is an R package that incorporates a number of […]

## A demonstration of vtreat data preparation

This article is a demonstration the use of the R vtreat variable preparation package followed by caret controlled training. In previous writings we have gone to great lengths to document, explain and motivate vtreat. That necessarily gets long and unnecessarily feels complicated. In this example we are going to show […]

## Improved vtreat documentation

Nina Zumel has donated some time to greatly improve the vtreat R package documentation (now available as pre-rendered HTML here). vtreat is an R data.frame processor/conditioner package that helps prepare real-world data for predictive modeling in a statistically sound manner.