フリー問題

問題文

A team reads the MLlib guide and wants to know which of the two central abstractions performs the learning step. Which statement separates the two correctly?

選択肢

1. An estimator scores a frame and yields a metric while a transformer stores the learned weights of the model inside the frame.
2. An estimator learns from a frame and yields a transformer while a transformer turns one frame into another frame by adding columns.
3. A transformer scores a frame and yields a metric while an estimator copies the columns of the input into the output frame.
4. A transformer learns from a frame and yields an estimator while an estimator turns one frame into another frame by adding columns.