Machine learning in practice

Real data is not a tidy table of numbers.

Categories and features

The same flats, turned into numbers in different ways.

The data as the model sees it

The first rows, after the choices above.

Predicted against real price, validation flats

The weights

One weight per column.

Your tries

ChoicesValidation RMSE

A project from start to finish

Every step that learns from the data is fitted on the training part only.

  1. Split the data first.
  2. Fit every step on the training part only.
  3. Apply the same fitted steps to the validation data.
  4. At the very end, test once on the test set.

Validation says
On new data