Tip: To obtain decision rate matrices for a response using the default profit matrix with costs of 1 and -1, select Specify Profit Matrix from the red triangle menu, make no changes to the default values, and click OK.
Select Help > Sample Data Library and open Liver Cancer.jmp.
Select Analyze > Modeling > Partition.
Select Severity and click Y, Response.
Select BMI through Jaundice and click X, Factor.
Click Split ten times.
Panel Showing Summary of Split
Completed Profit Matrix
Confusion Matrix and Decision Matrix Reports
The first three columns involve only the predicted probabilities. The confusion matrix counts are based on the Most Likely Severity column, which classifies a patient into the level with the highest predicted probability. These probabilities are given in the Prob(Severity == High) and Prob(Severity == Low) columns.
The last five columns involve the profit matrix weighting. The column called Most Profitable Prediction for Severity contains the decision based on the profit matrix. The decision for a patient is the level that results in the largest profit. The profits are given in the Profit for High and Profit for Low columns.
The Confusion Matrix in Confusion Matrix and Decision Matrix Reports shows classifications based on predicted probabilities alone. Based on these, 33 High severity patients would be classified as Low severity and 5 Low severity patients would be classified as High severity. The Decision Matrix report incorporates the weights in the profit matrix. Using those weights, only 5 High severity patients are classified as Low severity. However, this comes at the expense of misclassifying 38 Low severity patients into the High severity group.