Model Metrics

Marketinganalyse: klantverloop voorspellen in Python

Mark Peterson

Director of Data Science, Infoblox

Imbalanced classes

telco['Churn'].value_counts()
no     2850
yes     483
Name: Churn, dtype: int64
  • Accuracy not a very useful metric
Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 1

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 2

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 3

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 4

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 5

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 6

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 7

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 8

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 9

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 10

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 11

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix Part 12

Marketinganalyse: klantverloop voorspellen in Python

Precision

Metric Formula
Precision True Positives / (True Positives + False Positives)

 

  • A model with high precision indicates:
    • Few false positives ("false alarms")
    • Not many non-churners were classified as churners
Marketinganalyse: klantverloop voorspellen in Python

Recall

Metric Formula
Recall/Sensitivity True Positives / (True Positives + False Negatives)

 

  • A model with high recall indicates that it correctly classified most churners
Marketinganalyse: klantverloop voorspellen in Python

Precision vs. Recall

Marketinganalyse: klantverloop voorspellen in Python

Confusion Matrix in scikit-learn

from sklearn.metrics import confusion_matrix

cm = confusion_matrix(y_test, y_pred)
Marketinganalyse: klantverloop voorspellen in Python

Let's practice!

Marketinganalyse: klantverloop voorspellen in Python

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