4.2 Judge, Jury, and Classifier: An Introduction to Trees

4.2 Judge, Jury, and Classifier: An Introduction to Trees

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?

Exercise 1

 Numerical Response 

 

Explanation

The fraction of observations that have outcome A is 14/20 = 0.7.

CheckShow Answer

 

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?

Exercise 2

 A 

 B 

If we set the threshold to 0.5 when computing predictions of outcome A, will we predict A or B for these observations?

Exercise 3

 A 

 B 

If we set the threshold to 0.75 when computing predictions of outcome A, will we predict A or B for these observations?

Exercise 4

 A 

 B 

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.

CheckShow Answer

 

Course Info

Learning Resource Types

theaters Lecture Videos
notes Lecture Notes
assignment_turned_in Problem Sets with Solutions