| SAS defines data mining as the process of uncovering hidden patterns in large amounts of data. Many industries use data mining to address business problems and opportunities such as fraud detection, risk and affinity analyses, database marketing, householding, customer churn, bankruptcy prediction, and portfolio analysis.The SAS data mining process is summarized in the acronym SEMMA, which stands for sampling, exploring, modifying, modeling, and assessing data.
- Sample the data by creating one or more data tables. The sample should be large enough to contain the significant information, yet small enough to process.
- Explore the data by searching for anticipated relationships, unanticipated trends, and anomalies in order to gain understanding and ideas.
- Modify the data by creating, selecting, and transforming the variables to focus the model selection process.
- Model the data by using the analytical tools to search for a combination of the data that reliably predicts a desired outcome.
- Assess the data by evaluating the usefulness and reliability of the findings from the data mining process.
You might not include all of these steps in your analysis, and it might be necessary to repeat one or more of the steps several times before you are satisfied with the results. After you have completed the assessment phase of the SEMMA process, you apply the scoring formula from one or more champion models to new data that might or might not contain the target. The goal of most data mining tasks is to apply models that are constructed using training and validation data in order to make accurate predictions about observations of new, raw data.
The SEMMA data mining process is driven by a process flow diagram, which you can modify and save. The GUI is designed in such a way that the business analyst who has little statistical expertise can navigate through the data mining methodology, while the quantitative expert can go “behind the scenes” to fine-tune the analytical process.
SAS Enterprise Miner 5.2 contains a collection of sophisticated analysis tools that have a common user-friendly interface that you can use to create and compare multiple models. Statistical tools include clustering, self-organizing maps / Kohonen, variable selection, trees, linear and logistic regression, and neural networking. Data preparation tools include outlier detection, variable transformations, data imputation, random sampling, and the partitioning of data sets (into train, test, and validate data sets). Advanced visualization tools enable you to quickly and easily examine large amounts of data in multidimensional histograms and to graphically compare modeling results. |
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