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Question 1

In the file ~cs322/cilog/dtlearn1.pl is an axiomatization of a decision-tree learning algorithm. This works with the data in the file ~cs322/cilog/dtlearn_t1.pl, and produces the tree of Figure 11.3 of the textbook.

This uses a complicated procedure to determine what is the best attribute to split on. In this question, you will look at what happens when this procedure is changed.

Suppose you change the procedure select_split so that it always selects the first element of the list of attributes. What tree is found when the attributes are in the order [author, thread, length, where_read]? Does this tree represent a different function than that found with the more complicated selection mechanism? Explain.
What tree is found when the attributes are in the order [where_read, thread, length, author]? Does this tree represent a different function than that found with the more complicated selection mechanism or the one given for the preceding part? Explain.
Is there a tree that correctly classifies the training examples, but represents a different function than those found by the preceding algorithms? If so, give it. If not, explain why.

Solution to Question 1, part 1

Solution to Question 1, part 2

Solution to Question 1, part 1