Book Image

IBM SPSS Modeler Cookbook

Book Image

IBM SPSS Modeler Cookbook

Overview of this book

IBM SPSS Modeler is a data mining workbench that enables you to explore data, identify important relationships that you can leverage, and build predictive models quickly allowing your organization to base its decisions on hard data not hunches or guesswork. IBM SPSS Modeler Cookbook takes you beyond the basics and shares the tips, the timesavers, and the workarounds that experts use to increase productivity and extract maximum value from data. The authors of this book are among the very best of these exponents, gurus who, in their brilliant and imaginative use of the tool, have pushed back the boundaries of applied analytics. By reading this book, you are learning from practitioners who have helped define the state of the art. Follow the industry standard data mining process, gaining new skills at each stage, from loading data to integrating results into everyday business practices. Get a handle on the most efficient ways of extracting data from your own sources, preparing it for exploration and modeling. Master the best methods for building models that will perform well in the workplace. Go beyond the basics and get the full power of your data mining workbench with this practical guide.
Table of Contents (17 chapters)
IBM SPSS Modeler Cookbook
Credits
Foreword
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Quantifying variable importance with Monte Carlo simulation


Finding the smallest subset of all possible input variables that result in an accurate model (that is, a parsimonious solution) is often the biggest challenge for many data mining projects. It's common for data sets to contain 10s to 100s of input variables. Models that are over-trained or simply fail to build are both possible with so called "wide" data sets. Removing unimportant variables to find the sweet spot between model accuracy and stability is where experienced data miners can deliver significant value.

The primary method of variable selection in Modeler is Feature Selection. The Feature Selection process identifies the significance of each variable individually. Statistically insignificant variables below a specified p-value are dropped. While this technique works well with simple data sets and "main effects" models such as regression, it completely ignores the interaction between variables. As often happens, the interaction...