Is the answer a label or a number?
Direct answer
Classification predicts a category, such as "spam" or "not spam". Regression predicts a number, such as the price of a house. Ask whether your target is a label or a quantity, then choose algorithms and metrics to match.
Examples
| Task | Type |
|---|---|
| Is this email spam? | classification |
| Which digit is this image? | classification |
| What will this house sell for? | regression |
| How many units will sell next week? | regression |
Metrics
- Classification: accuracy, precision, recall, F1.
- Regression: MAE, MSE, R squared.
Algorithms
- Classification: logistic regression, decision trees, random forests.
- Regression: linear regression, decision trees, gradient boosting.
Where Teyro fits
Teyro's Machine Learning for Beginners course turns this into short lessons you can play in a few minutes a day. It has 200 lessons, and you can start free.
The bottom line
Label or number: that decides your approach.
