Why are training set and test set kept separate?

A. model को fair तरीके से evaluate करने के लिए / To evaluate model fairly

Step 1: Identify the concept: this is model evaluation. Step 2: The model learns from training data and test data checks its performance on new examples. Step 3: Remember train for learning and test for checking.

Step 1: concept पहचानें: यह model evaluation है। Step 2: Model training data से सीखता है और test data से नए examples पर उसकी performance जांची जाती है। Step 3: Train for learning test for checking याद रखें।