Question: Consistency is a popular feature subset evaluation measure. The measure is motived by the idea that a good feature subset should have high consistency or

Consistency is a popular feature subset evaluation measure. The measure is motived by the idea that a good feature subset should have high consistency or low inconsistency among matching instances. Two instances are considered matching instances if their values of all features (except the class) match. For 2 matching instances, an inconsistency occurs if their class values are different. For n matching instances, the number of inconsistencies (i.e., inconsistency count) is determined by n max{m0, m1}, where m0+m1=n, and m0 and m1 are the number instances for class 0 and class 1 respectively. In other words, it is the count of the instances in the minority class. For example, if we only consider the data in the two columns of F1 and C (ignoring features F2, F3, and F4), there are 4 matching instances with F1 being 1. The inconsistency count for this set of matching instances is 4-max{2,2}=2. Similarly, there are 4 matching instances with F1 being 0, and the same inconsistency count 2. The total inconsistency count for F1 is 2+2=4. Consider the following data with four binary features (F1, F2, F3, and F4) and binary class label C. Perform feature selection using Sequential Backward Selection (SBS) search coupled with total inconsistency count as the subset evaluation measure (smaller inconsistency is better). What will be the selected subset of two features (illustrate your solution by intermediate steps)? F1(1,1,1,0,1,0,0,0) F2(1,1,0,1,0,0,0,1) F3(1,0,0,0,1,1,0,1) F4(1,1,0,0,0,1,0,1) C (1,1,0,0,0,1,1,0)(20 points) For the same data set above, if Sequential forward Selection (SFS) is used with the same subset evaluation measure, what will be the selected subset of two features (illustrate your solution)?3.(10 points) Discuss which method, SBS or SFS, is better for the above data and why?

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