Machine Learning · Chapter 16 of 40
Naive Bayes
NAIVE BAYES applies Bayes' theorem assuming features are INDEPENDENT — 'naive' because they usually aren't.
Surprisingly effective for text classification (spam, sentiment).
Example 1 (python)
from sklearn.naive_bayes import MultinomialNB
m = MultinomialNB().fit(X_train, y_train)
print(m.score(X_test, y_test))Output
0.87Very fast to train.
Example 2 (python)
# GaussianNB for continuous, MultinomialNB for counts, BernoulliNB for binaryPick the variant to match your data.
Key points
- Based on Bayes' theorem.
- Assumes feature independence.
- Very fast to train.
- Great baseline for text.
💡 Note: Multinomial Naive Bayes on TF-IDF features is a strong, cheap baseline for spam and sentiment tasks.
