What are some examples of confusion matrices?

What are some examples of confusion matrices?

A confusion matrix is a table used to evaluate the performance of a classification model. It shows the true positives, false positives, true negatives, and false negatives. Would you like to see a specific example?

Yes, please provide an example with numbers.

Sure! Let's say we have a binary classification model that predicts whether an email is spam or not. Here’s a confusion matrix:

| | Predicted Spam | Predicted Not Spam | |----------------|----------------|--------------------| | Actual Spam | 50 (TP) | 10 (FN) | | Actual Not Spam| 5 (FP) | 100 (TN) |

This means the model correctly identified 50 spam emails and incorrectly identified 5 non-spam emails as spam.

What do TP, FP, TN, and FN stand for?

TP stands for True Positives, FP for False Positives, TN for True Negatives, and FN for False Negatives. They help in understanding the model's accuracy.

How can I calculate accuracy from a confusion matrix?

Accuracy can be calculated using the formula:

Accuracy = (TP + TN) / (TP + TN + FP + FN)

Using our example, it would be (50 + 100) / (50 + 100 + 5 + 10) = 0.93 or 93%.