1. Enter the data first: here, the serial number 1 stands for hit, and 0 stands for false report. The "Frequency" column below corresponds to the frequencies of hits and false positives, and the predetermined probabilities are 0.2/0.5/0.8 respectively.

2. Secondly, open "Analysis" for frequency weighting, and a "ROC curve" will appear at the bottom. Open and drag Frequency to the test variable column, and drag Serial Number to the state variable column.

3. The value of the state variable is set to "1".

4. Click ROC curve, diagonal reference line and ROC curve coordinate point to confirm.

5. This original ROC curve will appear later.