Quick Question
Suppose you have a subset of 20 observations, where 14 have outcome A and 6 have outcome B. What proportion of observations have outcome A?
Explanation
The fraction of observations that have outcome A is 14/20 = 0.7.
Quick Question
The following questions ask about the subset of 20 observations from the previous question.
If we set the threshold to 0.25 when computing predictions of outcome A, will we predict A or B for these observations?
If we set the threshold to 0.5 when computing predictions of outcome A, will we predict A or B for these observations?
If we set the threshold to 0.75 when computing predictions of outcome A, will we predict A or B for these observations?
Explanation
Since 70% of these observations have outcome A, we will predict A if the threshold is below 0.7, and we will predict B if the threshold is above 0.7.