04. Confusion Matrix

Confusion Matrix

Confusion Matrix-Question 1

In this image, the blue points are labelled positive, and the red points are labelled negative. Furthermore, the points on top of the line are predicted (guessed) to be positive, and the points below the line are predicted to be negative.

In this image, the blue points are labelled positive, and the red points are labelled negative.
Furthermore, the points on top of the line are predicted (guessed) to be positive, and the points below the line are predicted to be negative.

Confusion Matrix Quiz

QUESTION:

How many True Positives, True Negatives, False Positives, and False Negatives, are in the model above?
Please enter your answer in that order, as four numbers separated by a comma and a space. For example, if your answers are 1, 2, 3, and 4, enter the string 1, 2, 3, 4 .

Remember, in the image above the blue points are considered positives and the red points are considered negatives.

SOLUTION:

NOTE: The solutions are expressed in RegEx pattern. Udacity uses these patterns to check the given answer

Type 1 and Type 2 Errors

Sometimes in the literature, you'll see False Positives and False Negatives as Type 1 and Type 2 errors. Here is the correspondence:

  • Type 1 Error (Error of the first kind, or False Positive): In the medical example, this is when we misdiagnose a healthy patient as sick.
  • Type 2 Error (Error of the second kind, or False Negative): In the medical example, this is when we misdiagnose a sick patient as healthy.

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