AI Engineering Degree Practice Exam 2026 - Free AI Engineering Practice Questions and Study Guide

When the information gain using an attribute A is calculated to be 0.3, this value represents the decrease in entropy resulting from the split based on that attribute. Specifically, information gain is defined as the difference between the entropy of the dataset before the split and the weighted entropy of the subsets after the split. Therefore, if the information gain is 0.3, it indicates that the entropy of the original dataset minus the weighted entropy of the subsets formed by the split is equal to 0.3. This means that attribute A provides useful information that helps to reduce uncertainty about the classification of the data, reflecting a meaningful impact on the decision tree's predictive power.

The concept of information gain is a crucial measurement in decision tree algorithms, marking how well a particular attribute contributes to making the target variable more predictable after the split.