SPSS AnswerTree 3.1

How do you determine which customer, or citizen group, best matches your offerings or programs? What if you had a way to avoid spending a lot of money and time trying to reach people and instead could more efficiently reach them—and increase your return on investment?

Segmentation eliminates the guesswork
The segmentation capabilities in AnswerTree enable you to more accurately target people and eliminate the guesswork that many direct mail software solutions impose. Results from AnswerTree can complement your direct mail software and eliminate your need to send offers to arbitrary groups of people—or everyone—on your mailing list.

Four powerful decision trees—including CHAID—to fit your data
AnswerTree enables you to more efficiently target the right groups of people. Use scalable decision trees to reveal segments and predict how groups will respond to your promotions and programs. AnswerTree gives you the widest choice of decision trees available through four powerful algorithms, including CHAID, so you can choose the best fit for your data.

AnswerTree visually displays decision tree models—so you can easily see the groups that matter. At-a-glance evaluation graphs enable you to act on results quickly. Answer Tree's unrivaled analytical power, scalability, and presentation features give you a smarter, more effective way to discover significant groups and create profiles.

AnswerTree 3.1 is available in English, Japanese, French, German, Italian, and Spanish.


How decision tree results are different in AnswerTree 3.1/3.0

AnswerTree 3.1/3.0 has implemented consistent rules for handling ties between predictors when determining splits. In the past, AnswerTree did not always follow consistent rules about what to do in case of a tie. The most obvious result of these rules is that some trees developed in previous versions of AnswerTree will look different if built in AnswerTree 3.1/3.0.

Because these tie-breaking rules affect more extreme situations and are often arbitrary decisions, the results in any version are equally valid. For example, in C&RT, the order that the predictor was added to the model-an arbitrary rule-determines the split. The difference is that now you can understand and explain how a split is made in these situations. It is also worth noting that in these situations it may be worth using AnswerTree's interactive tree building features to choose the predictor, since you may be more interested in including one attribute instead of another equally significant predictor.

The algorithms use different rules to determine which predictor to use. For example, with a continuous target, CHAID will choose the predictor whose split gives the most significantly different groups of the target. For a categorical target, CHAID selects the predictor whose measure of independence with the target is smallest. (See Appendix E in the AnswerTree User's Guide for details.) If there is a "tie" between two predictors, then AnswerTree needs to choose one predictor over another. In 3.1/3.0 the rules are always consistent:

For CHAID & Exhaustive CHAID:
The split rule with lower p value is listed first
In case of tie, the rule with higher F (or Chi-Square) is listed first
In case of tie, the rule with lower DF is listed first
In case of tie, the rule whose associated predictor variable was added first to the model is listed first

For QUEST:
The split rule with lower p value is listed first
In case of tie,

• Order among all the tied Chi-Square. The larger value listed first.
• If there are ties in the item above, order by DF. The smaller DF listed first.
• Order among all the tied F (F or Levene's F). The larger value listed first.
• If there are ties in the item above, order by DF1+DF2 with the larger sum listed first. If there still is a tie, order by DF1 with the smaller value listed first. (note: sort by DF1+DF2 will put the predictor with fewer missing values before predictor with more missing values)
• To set ordering among these two groups (Chi-Square group and F group), list first the predictor added first to the model

• Enhanced scalability and performance — more effectively solve enterprise-sized problems. Disk space requirements for processing large data files are now reduced due to the use of cache compression and improved temporary file management.
• Enhanced tree duplication — get enhanced efficiency. You now have the ability to create new trees based on existing trees in the project.
• Show split statistics — enhance your model understanding and insight by showing/hiding split statistics conveniently within the tree. For splits using ordinal predictor variables, you can display categories as ranges or discrete values.
• Repeatable tasks are simplified — simplify repeatable tasks (such as running weekly reports). You can now generate scripts automatically from the user interface and run them on a Solaris or Windows NT platform.
• Enhanced connectivity with other SPSS Inc. products — extend your export options; the production mode now exports PMML-compliant files. For instance, use SmartScore to interpret AnswerTree's PMML models and use them to score new cases.
• General Usability Enhancements —
• Get added control and efficiency. The Data Properties dialog box now allows you to view data properties before creating the root node.
• More efficiently define intervals for continuous predictor variables in CHAID analyses by using the Intervals tab in the Advanced Options dialog box. Access this dialog from the new Tree Wizard or from the Analysis menu after the tree is grown.
• More efficiently change the measurement level of predictor variables using the Measurement Level dialog box. You can also change measurement levels before you grow the tree in the Model Definition step of the New Tree Wizard.
• The Define Variables dialog box has been eliminated. Perform the same tasks more efficiently using the new Data Properties and Measurement Level dialog boxes and the Advanced Options, Intervals tab.
• Enhanced robustness — many underlying enhancements enable you to explore your data with unprecedented levels of convenience, control, and confidence

• AnswerTree client

• AnswerTree server