Building credit scorecards using credit scoring for sas. Creating and interpreting decision trees in sas enterprise miner. So lets run the program and take a look at the output. In chaid analysis, the following are the components of the decision tree. To illustrate with a relatable example, imagine solving the problem of being hungry.
The decision trees optional addon module provides the additional analytic techniques described in this manual. An introduction to classification and regression trees with proc. On the other hand, in order to find out the most desired output given the combination of variables, a decision tree with proc. Because no style template is specified, the default style, styles. Root node contains the dependent, or target, variable. Feature selection and dimension reduction techniques in sas varun aggarwal sassoon kosian exl service, decision analytics abstract in the field of predictive modeling, variable selection methods can significantly drive the final outcome. Dec 12, 2017 chaid ch isquare a utomatic i nteraction d etector analysis is an algorithm used for discovering relationships between a categorical response variable and other categorical predictor variables. Building a classification tree for a binary outcome. Chaid analysis decision tree analysis b2b international. Dec 29, 2011 a link on the right provides information about chaid. Beginning a chaid analysis statistical innovations. For example, chaid is appropriate if a bank wants to predict the credit card risk.
This includes how the chaid algorithm differs from the decision tree node and how it can be approximated. Introduction to statistical analysis with sas david gerbing. The advantage of chaid is that the output is highly visual and easy to interpret. The following discussion provides a brief description of the chaid chisquare automatic interaction detection algorithm for building decision trees. When i create a graph and write it to a pdf with ods, the result looks fine in the sas eg report window but the pdf output gets rasterized to the dpi setting of the pdf so if you zoom into the pdf you can make out pixelation. Building a decision tree with sas decision trees coursera. Chaid analysis is used to build a predictive model to outline a specific customer group or segment group e.
Creating the perfect table using ods to pdf in sas 9. You cannot print the file until you close the destination. Analytic experts can further customize and improve sas rpm developed models using sas enterprise miner. Actions close close the pdf destination and the file that is associated with it. Again, we run a regression model separately for each of the four race categories in our data. If you run this program in sas enterprise guide without turning off the other results formats, the final pdf output wont have all of the attributes you expect. Output as with creating a pdf file with multiple graphs, the sas graph output can be combined with output from other procedures. Take control of ods results in sas enterprise guide the sas. For example, chaid is appropriate if a bank wants to predict the credit card risk based upon information like age, income, number of credit cards, etc.
In chaid analysis, nominal, ordinal, and continuous data can be used, where continuous predictors are split into categories with approximately equal number of observations. Sas provides birthweight data that is useful for illustrating proc hpsplit. The hpsplit procedure uses ods graphics to create plots as part of its output. Chaid chisquare automatic interaction detector select. You can control the style and attributes of the output, thus creating a customized report. Ibm spss statistics is a comprehensive system for analyzing data. The input statement also names the variables for a sas analysis. This is done by using the ods statement available in sas. The class, model, id and output statements work in more or less familiar ways, although there are. Anyone have hints for getting clean pdf output from proc sgplot and similar functions like sgscatter. Sas has implemented cart with both enterprise miner and visual.
Decision trees for business intelligence and data mining. Decision trees produce a set of rules that can be used to generate predictions for a new data set. We can see in the model information information table that the decision tree that sas grew has 252 leaves before pruning and 20 leaves following pruning. Chisquare automatic interaction detection chaid is a decision tree technique, based on adjusted significance testing bonferroni testing. Chaid analysis or regression selection procedure stepwise, forward or backward. This helps to solve some important problems, facing a modelbuilder. Statistical analysis allows us to use a sample of data to make predictions about a larger population. Jan 09, 2017 the preceding paragraph oversimplifies the sas output delivery system ods, but the truth is that ods is a powerful feature of sas. Oct 07, 2016 creating and interpreting decision trees in sas enterprise miner. The trunk of the tree represents the total modeling database. The process of building a decision tree begins with growing a large, full tree. Applying chaid for logistic regression diagnostics and.
The decision trees addon module must be used with the spss statistics core system and is completely integrated into that system. To begin a chaid analysis, we need to select one or more dependent variables and at least one predictor. The sas output delivery system ods statement provides a flexible way to store output in various formats, such as html, pdf, ps postscript, and rtf suit. The output from a sas program can be converted to more user friendly forms like. Apr 16, 2014 sas enterprise guide will offer to download this file for you to view, but if you want complete control over where it lands on your local pc, use the copy files task to download it. Gerbing isqa 521 introduction to sas 2 of 14 the next row of the sas data set. We would like to show you a description here but the site wont allow us. Guide to segmentation for survival models using sas. The pdftoc2 option specifies that the table of contents is expanded two levels. A modification of chaid that examines all possible splits for each predictor. Advanced modelling techniques in sas enterprise miner sas. If no data set name is specified in the output statement, the observation is written to the data set or data sets that are listed in the data statement. Use the options statement between the steps that create output to change the page orientation. Create two different pdf output files at the same time.
The goal of a decision tree is to ascertain the most desirable outcome given the. At each step, chaid chooses the independent predictor variable that has the strongest interaction with the dependent variable. The chaid algorithm parses a predictor variable into its most distinct subgroups with respect to the dependent variable, while preserving parsimony and adjusting for alpha inflation type i error. Because no style definition is specified, the default style, styles. Chisquare automatic interaction detector chaid was a technique created by. Once the ods pdf destination is opened, the output is sent to the named file. Creating a decision tree analysis using spss modeler. For this analysis, the dichotomous variable resp2 will be the single dependent variable. Using sas ods to create adobe pdfs from sasgraph output. While the focus of the analysis may generally be to get the most accurate predictions.
It is mostly used to format the output data of a sas program to nice reports which are good to look at and understand. Optionally, one of two weight variables can be specified a case weight frequency and a sampling weight weight. The technique was developed in south africa and was published in 1980 by gordon v. Feature selection and dimension reduction techniques in sas. Opens, manages, or closes the pdf destination, which produces pdf output, a form of output that is read by adobe acrobat and other applications.
The output statement tells sas to write the current observation to a sas data set immediately, not at the end of the data step. Finally, after specifying my grow and prune choices, i end my program with a run statement. Below, we run a regression model separately for each of the four race categories in our data. This information can then be used to drive business decisions. Pdf technological advancement across human activities has. A basic introduction to chaid chaid, or chisquare automatic interaction detection, is a classification tree technique that not only evaluates complex interactions among predictors, but also displays the modeling results in an easytointerpret tree diagram. Example this example creates a pdf file with both portrait and landscape orientations.
Sas ite aper the power of sas software to access and transform data on a huge variety of systems ensures that modeling with sas enterprise miner smoothly integrates into the larger creditscoring process. This is a step prior to the actual model building exercise, and is about dividing the population into segments which are homogeneous within themselves and heterogeneous amongst themselves, so that separate probability of default models can be developed on each of these segments. Kass, who had completed a phd thesis on this topic. Example of decimal alignment conclusion creating pdf output requires different statements than other output types. How can i generate pdf and html files for my sas output. Applying chaid for logistic regression diagnostics and classification accuracy improvement abstract in this study a chaid based approach to detecting classification accuracy heterogeneity across segments of observations is proposed. It is useful when looking for patterns in datasets with lots of categorical variables and is a convenient way of summarising the data as the. The development of the decision, or classification tree, starts with identifying the target variable or dependent variable which would be considered the root. How can i store sas output in html, pdf, ps, or rtf format. For example, in database marketing, decision trees can be used to develop customer profiles that help marketers target promotional mailings in order to generate a higher response rate. Chose from prebuilt enterprise miner models that use a broad range of classical and modern modeling techniques. Sas software is the ideal tool for building a risk data warehouse. Application of sas enterprise miner in credit risk analytics. Categories of each predictor are merged if they are not significantly different with respect to the dependent variable.
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