Solved: 16. You are asked to evaluate the performance of two classification mo

Question

16. You are asked to evaluate the performance of two classification models, M₁ and M2. The test set you have chosen contains 26 binary attributes, labeled as A through Z. Table 4.5 shows the posterior probabilities obtained by applying the models to the test set. (Only the posterior probabilities for the positive class are shown). As this is a two-class problem, P(-) = 1 − P(+) and P(-|A,..., Z) = 1 - P(+A,,Z). Assume that we are mostly interested in detecting instances from the positive class. Table 4.5. Posterior probabilities for Exercise 16. Instance True Class | P(+|A,..., Z, M₁) | P(+|A, ………, Z, M2) 1 2 3 4 6 7 9 10 ++ || ++11 +1 0.73 0.61 0.69 0.03 0.44 0.68 0.55 0.31 0.67 0.45 0.47 0.09 0.08 0.38 0.15 0.05 0.45 0.01 0.35 0.04 (a) Plot the ROC curve for both M₁ and M2. (You should plot them on the same graph.) Which model do you think is better? Explain your reasons.