I recently took an online quiz on Machine Learning. One question was particularly confusing to me. The question is stated below.
Consider a dataset Z on which a decision tree is built. Consider the split attribute learnt at the root of the decision tree. Which of the following will hold True if one of the data points in the dataset is removed and the tree is rebuilt?
(a) The split attribute at the root will be exactly the same as before
(b) The split attribute could be the same or could be different
(c) The split attribute cannot be done as the dataset is incomplete
I ticked the option (b) because if the gini index of the model is different after removing one particularly critical data point, the split attribute would change. However, if a data point which does not influence gini index enough is removed, then the model might retain the same split attribute. Can anyone help me clear the doubt? Thanks!