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A model flags 200 emails as spam; 150 really are. What is its precision?
0.75, which is 150 out of 200.
- 0.25
- 0.75 ✔
- 1.33
Why: Precision asks: when the model said positive, how often was it right? True positives divided by all positive predictions: 150 over 200 is 0.75.
Huh, didn't know that: The 50 wrong flags are false positives: real email sent to the spam folder.
My spam filter has 75 percent precision. The other 25 percent was my grandma's emails.
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References
Answer: 0.75. Precision asks: when the model said positive, how often was it right? True positives divided by all positive predictions: 150 over 200 is 0.75.
- Google Machine Learning Glossary: precision developers.google.com/machine-learning/glossary
When the model predicted the positive class, what percentage of the predictions were correct?
Checked 2026-10-10.
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