Question

Calculate Accuracy, Precision, Recall and F1 Score for the following Confusion Matrix on Water Shortage in Schools: Also suggest which metric would not be a good evaluation parameter here and why?

Answer 1

The Confusion Matrix (Water Shortage in School)	Reality: 1	Reality: 0
Prediction: 1	75	5
Prediction: 0	5	15

	Reality: 1	Reality: 0
Prediction: 1	75	5	80
Prediction: 0	5	15	20
	80	20	100

Calculation:

Accuracy: Accuracy is defined as the percentage of correct predictions out of all the observations.

Where True Positive (TP), True Negative (TN), False Positive (FP) and False Negative (FN).

= (75+15) / (75+15+5+5) 

= (90 / 100) 

=0.9

Precision: Precision is defined as the percentage of true positive cases versus all the cases where the prediction is true.

= 75 / (75+5) 

= 75 /80 

= 0.9375

Recall: It is defined as the fraction of positive cases that are correctly identified.

= 75 / (75+5) 

= 75 /80 

= 0.9375

F1 Score: F1 score is defined as the measure of balance between precision and recall.

= 2 * ((0.9375 *0.9375) / (0.9375+0.9375)

Therefore

= 2 * (0.8789 / 1.875) 

= 2 * 0.46875 

= 0.9375

Accuracy= 0.9% Precision=0.9375% Recall=0.9375%

F1 Score=0.

Here precision, recall, accuracy, f1 score all are same