2. The Value Add of Data Mining Segmentation 101 Segmentation Tools in Analysis Services Methodology for Segmentation Analysis Building Confidence in your Model 2 Agenda
4. Statistics for the Computer Age Evolution, not revolution with traditional statistics Statistics enriched with brute-force capabilities of modern computing Associated with industrial-sized data sets 4 Value Add - What is Data Mining?
5. 5 Data Mining OLAP Reports (Ad hoc) Reports (Static) Value Add - Data Mining in the BI Spectrum Business Knowledge SQL-Server 2008 Relative Business Value Easy Difficult
6. VoterVault From Mid-1990s Massive get-out-the-vote drive for those expected to vote Republican Demzilla Names typically have 200 to 400 information items 6 Value Add – Data Mining and Democracy
7. “The quiet statisticians have changed our world; not by discovering new facts or technical developments, but by changing the ways that we reason, experiment and form our opinions.” -- Ian Hacking Value Add – The Promise of Data Mining 7
10. Value Add – Strategic Benefits The Bottom Line Increased agility Brand building Differentiate message “Relationship” building
11. Value Add – Tactical Benefits Reduction of costs Transactional leakage Outlier analysis
12. Identify a group of customers who are expected to attrite Conduct marketing campaigns to change the behavior in the desired direction change their behavior, reduce the attrition rate. Value Add - Customer Attrition Analysis
13. Slow attriters: Customers who slowly pay down their outstanding balance until they become inactive. Fast attriters: Customers who quickly pay down their balance and either lapse it or close it via phone call or write in. Value Add - Target Result
16. Unsupervised learning Associations and patterns many entities target information Market basket analysis (“diapers and beer”) Supervised learning Predict the value target variable well-defined predictive variables Credit / non-credit scoring engines 16 Segmentation – Machine Learning
17. Segmentation –Sample Data Sources Data Warehouse: Credit Card Data Warehouse containing about 200 product specific fields Third Party Data : A set of account related demographic and credit bureau information Segmentation files :Set of account related segmentation values based on our client's segmentation scheme which combines Risk, Profitability and External potential Payment Database :Database that stores all checks processed. The database can categorize source of checks
21. Research/Evaluate possible data sources Availability Hit rate Implementability Cost-effectiveness Extract/purchase data Check data for quality (QA) At this stage, data is still in a “raw” form Often start with voluminous transactional data Much of the data mining process is “messy” Methodology – Acquiring Raw Data 21
22. Reflects data changes over time. Recognizes and removes statistically insignificant fields Defines and introduces the "target" field Allows for second stage preprocessing and statistical analysis. Methodology – Goals of Refinement
23. Scoring engine Formula that classifies or separates policies (or risks, accounts, agents…) into profitable vs. unprofitable Retaining vs. non-retaining… (Non-)Linear equation f() of several predictive variables Produces continuous range of scores score = f(X1, X2, …, XN) Methodology - Scoring Engines 23
24. Data To Predict Training Data Mining Model Mining Model Mining Model Methodology – Deployed Model DB data Client data Application log “Just one row” New Entry New Txion DM Engine DM Engine Predicted Data
25. Randomly divide data into 3 pieces Training data Test data Validation data Use Training data to fit models Score the Test data to create a lift curve Perform the train/test steps iteratively until you have a model you’re happy with During this iterative phase, validation data is set aside in a “lock box” Score the Validation data and produce a lift curve Unbiased estimate of future performance Methodology - Testing 25
26. Examine correlations among the variables Weed out redundant, weak, poorly distributed variables Model design Build candidate models Regression/GLM Decision Trees/MARS Neural Networks Select final model 26 Methodology - Multivariate Analysis
28. Data Mining - Algorithm Matrix Segmentation Advanced Data Exploration Classification Forecasting Association Text Analysis Estimation Association Rules Clustering Decision Trees Linear Regression Logistic Regression Naïve Bayes Neural Nets Sequence Clustering Time Series
29. 29 Data Mining - SQL-Server Algorithms Decision Trees Time Series Neural Net Clustering Sequence Clustering Association Naïve Bayes Linear and Logistic Regression
38. Data Mining - Cross-Validation SQL Server 2008 X iterations of retraining and retesting the model Results from each test statistically collated Model deemed accurate (and perhaps reliable) when variance is low and results meet expectations
39. Data Mining - Microsoft Decision Trees Use for: Classification: churn and risk analysis Regression: predict profit or income Association analysis based on multiple predictable variable Builds one tree for each predictable attribute Fast
41. Data Mining - Microsoft Naïve Bayes Use for: Classification Association with multiple predictable attributes Assumes all inputs are independent Simple classification technique based on conditional probability
43. Data Mining - Clustering Applied to Segmentation: Customer grouping, Mailing campaign Also: classification and regression Anomaly detection Discrete and continuous Note: “Predict Only” attributes not used for clustering
45. Data Mining - Neural Network Applied to Classification Regression Great for finding complicated relationship among attributes Difficult to interpret results Gradient Descent method Output Layer Loyalty Hidden Layers Input Layer Age Education Sex Income
47. Data Mining - Sequence Clustering Analysis of: Customer behaviour Transaction patterns Click stream Customer segmentation Sequence prediction Mix of clustering and sequence technologies Groups individuals based on their profiles including sequence data
48. To discover the most likely beginning, paths, and ends of a customer’s journey through our domain consider using: Association Rules Sequence Clustering Data Mining - What is a Sequence?
50. Your “if” statement will test the value returned from a prediction – typically, predicted probability or outcome Steps: Build a case (set of attributes) representing the transaction you are processing at the moment E.g. Shopping basket of a customer plus their shipping info Execute a “SELECT ... PREDICTION JOIN” on the pre-loaded mining model Read returned attributes, especially case probability for a some outcome E.g. Probability > 50% that “TransactionOutcome=ShippingDeliveryFailure” Your application has just made an intelligent decision! Remember to refresh and retest the model regularly – daily? Data Mining – Minor Introduction to DMX
57. Which target variable to use? Frequency & severity Loss Ratio, other profitability measures Binary targets: defection, cross-sell …etc How to prepare the target variable? Period - 1-year or Multi-year? Losses evaluated @? Cap large losses? Cat losses? How / whether to re-rate, adjust premium? What counts as a “retaining” policy? …etc Building Confidence - Model Design 50
58. Approaches Change the algorithm Change model parameters Change inputs/outputs to avoid bad correlations Clean the data set Perhaps there are no good patterns in data Verify statistics (Data Explorer) Building Confidence - Improving Models
59. Capping Outliers reduced in influence and to produce better estimates. Binning Small and insignificant levels of character variables are regrouped. Box-Cox Transformations These transformations are commonly included, specially, the square root and logarithm. Johnson Transformations Performed on numeric variables to make them more ‘normal’. Weight of Evidence Created for character variables and binned numeric variables. 52 Building Confidence – Alternate Methods
60. 53 Building Confidence - Confusion Matrix 1241 correct predictions (516 + 725) . 35 incorrect predictions (25 + 10). The model scored 1276 cases (1241+35). The error rate is 35/1276 = 0.0274. The accuracy rate is 1241/1276 = 0.9725.
61. “All models are wrong, but some are useful." George Box 54 Building Confidence – Warning Signs
62. Extrapolation Applying models from unrelated disciplines Equality The real world contains a surprising amount of uncertainty, fuzziness, and precariousness. Copula Binding probabilities can mask errors Distribution functions Small miscalculations can make coincidences look like certainties Gamma Human behavior difficult to quantify as a linear parameter 55 Building Confidence –Li’s Revenge
63. 56 Building Confidence - Lift Curves Sort data by score Break the dataset into 10 equal pieces Best “decile”: lowest score lowest LR Worst “decile”: highest score highest LR Difference: “Lift” Lift = segmentation power Lift translates into ROI of the modeling project
64. Building Confidence – Vetted Results ~Top 5% of 750000 2 groups with 10000 customers from random sampling 37500 top customers from the prediction list sorted by the score Group 1 Engaged or offered incentives by marketing department Group 2 No action Results Group 1 has a attrition rate 0.8%, Group 2 has 10.6% Average attrition rate is 2.2% Lift is 4.8 (10.6% /2.2%)
66. Xiaohua Hu, Drexel University Jerome Friedman, Trevor Hastie, Robert Tibshirani ,The Elements of Statistical Learning James Guszcza,Deloitte Jeff Kaplan, Apollo Data Technologies Rafal Lukawiecki, Project Botticelli Ltd David L. Olson, University of Nebraska Lincoln Donald Farmer, ZhaoHui Tang and Jamie MacLennan, Microsoft ASA Corporation Richard Boire, Boire Filler Group, John Spooner, SAS Corporation Shin-Yuan Hung , Hsiu-Yu Wang , National Chung-Cheng University Felix Salmon and Chris Anderson, Wired Magazine 59 Credits