Confusion matrices
You have just finished creating a classification model. This model predicts whether tweets were created by a left-leaning (democrat) or right-leaning (republican) tweet bot. You have made predictions on the test data and have the following result:
Predictions | Left | Right |
---|---|---|
Left | 350 | 157 |
Right | 57 | 436 |
Use the confusion matrix above to answer questions about the models accuracy.
This exercise is part of the course
Introduction to Natural Language Processing in R
Exercise instructions
- What percentage of tweets did you successfully label as
Left
? - What percentage of tweets did you successfully label as
Right
? - What percentage of tweets did you successfully label?
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Percentage correctly labeled "Left"
left <- (___) / (350 + 157)
left
# Percentage correctly labeled "Right"
right <- (___) / (___ + ___)
right
# Overall Accuracy:
accuracy <- (___ + ___) / (___ + ___ + ___ + ___)
accuracy