Information Gain in Decision Trees (Wikipedia) [optional reading]
We have spent a lot of time explaining the concept of entropy. Wikipedia page is rather mathematical and dry, but may be a good antidote to less formal and less organized exposition at the lecture. :)
Нажмите на ссылку https://en.wikipedia.org/wiki/Information_gain_in_decision_trees, чтобы открыть ресурс.