Exam 10: Data Mining

The Fisher classification scores can be converted to

Suppose that the observations are partitioned into m groups in equal proportion.The entropy measure for this situation is equal to

Suppose that all observations belong to the same class.The entropy measure for this situation is equal to

Exhibit 10.2 The following questions are based on the problem description,spreadsheet,and the Analytic Solver Platform Discriminant Analysis report below. A college admissions officer wants to evaluate graduate school applicants based on their GMAT scores,verbal and quantitative.Students are classified as either successful Group 1),marginally successful Group 2)or not- successful Group 3)in their graduate studies.The officer has data on 20 current students,7 successful Group 1),6 marginally successful Group 2)and 7 not successful Group 3). Discriminant Analysis Report October 1,2013 4:22:38 PM Unpooled Estimates of within-group Covariance matrices are used,assuming they are different. Group Centroids Group Quantitative Verbal 1 697.7142857 650.4285714 2 647.8571429 630.7142857 3 5876666667 6051666667 $\text {Group}$ $\text {Frenuencies}$ Group Relative Frequency 1 35.00\% 2 35.00\% 3 30.00\% Training Sample Classification Mahalanobis Distances $\text {Classification}$ $\text {Matrix}$ Actual / Predicted Group1 Group2 Group3 Total \% correct Group1 6 1 0 7 85.71\% Group2 0 7 0 7 100.00\% Group3 0 0 6 6 100.00\% Total 6 8 6 2 95.00\% -Refer to Exhibit 10.2.What number of observations is classified incorrectly?

Suppose that all observations in partition j belong to the same group.The Gini index for this situation is equal to

Exhibit 10.2 The following questions are based on the problem description,spreadsheet,and the Analytic Solver Platform Discriminant Analysis report below. A college admissions officer wants to evaluate graduate school applicants based on their GMAT scores,verbal and quantitative.Students are classified as either successful Group 1),marginally successful Group 2)or not- successful Group 3)in their graduate studies.The officer has data on 20 current students,7 successful Group 1),6 marginally successful Group 2)and 7 not successful Group 3). Discriminant Analysis Report October 1,2013 4:22:38 PM Unpooled Estimates of within-group Covariance matrices are used,assuming they are different. Group Centroids Group Quantitative Verbal 1 697.7142857 650.4285714 2 647.8571429 630.7142857 3 5876666667 6051666667 $\text {Group}$ $\text {Frenuencies}$ Group Relative Frequency 1 35.00\% 2 35.00\% 3 30.00\% Training Sample Classification Mahalanobis Distances $\text {Classification}$ $\text {Matrix}$ Actual / Predicted Group1 Group2 Group3 Total \% correct Group1 6 1 0 7 85.71\% Group2 0 7 0 7 100.00\% Group3 0 0 6 6 100.00\% Total 6 8 6 2 95.00\% -Refer to Exhibit 10.2.What percentage of observations is classified correctly?

Which of the following is not true regarding discriminant analysis?

A graphical representation of clustering outcomes showing which items should be classified to which clusters is called an)

Two approaches to clustering discussed in the text are

In the step of data mining,a researcher attempts to form logical groupings of data in the set

Exhibit 10.2 The following questions are based on the problem description,spreadsheet,and the Analytic Solver Platform Discriminant Analysis report below. A college admissions officer wants to evaluate graduate school applicants based on their GMAT scores,verbal and quantitative.Students are classified as either successful Group 1),marginally successful Group 2)or not- successful Group 3)in their graduate studies.The officer has data on 20 current students,7 successful Group 1),6 marginally successful Group 2)and 7 not successful Group 3). Discriminant Analysis Report October 1,2013 4:22:38 PM Unpooled Estimates of within-group Covariance matrices are used,assuming they are different. Group Centroids Group Quantitative Verbal 1 697.7142857 650.4285714 2 647.8571429 630.7142857 3 5876666667 6051666667 $\text {Group}$ $\text {Frenuencies}$ Group Relative Frequency 1 35.00\% 2 35.00\% 3 30.00\% Training Sample Classification Mahalanobis Distances $\text {Classification}$ $\text {Matrix}$ Actual / Predicted Group1 Group2 Group3 Total \% correct Group1 6 1 0 7 85.71\% Group2 0 7 0 7 100.00\% Group3 0 0 6 6 100.00\% Total 6 8 6 2 95.00\% -Refer to Exhibit 10.2.What is the verbal test score value of the group centroid for group 1?

Exhibit 10.2 The following questions are based on the problem description,spreadsheet,and the Analytic Solver Platform Discriminant Analysis report below. A college admissions officer wants to evaluate graduate school applicants based on their GMAT scores,verbal and quantitative.Students are classified as either successful Group 1),marginally successful Group 2)or not- successful Group 3)in their graduate studies.The officer has data on 20 current students,7 successful Group 1),6 marginally successful Group 2)and 7 not successful Group 3). Discriminant Analysis Report October 1,2013 4:22:38 PM Unpooled Estimates of within-group Covariance matrices are used,assuming they are different. Group Centroids Group Quantitative Verbal 1 697.7142857 650.4285714 2 647.8571429 630.7142857 3 5876666667 6051666667 $\text {Group}$ $\text {Frenuencies}$ Group Relative Frequency 1 35.00\% 2 35.00\% 3 30.00\% Training Sample Classification Mahalanobis Distances $\text {Classification}$ $\text {Matrix}$ Actual / Predicted Group1 Group2 Group3 Total \% correct Group1 6 1 0 7 85.71\% Group2 0 7 0 7 100.00\% Group3 0 0 6 6 100.00\% Total 6 8 6 2 95.00\% -Refer to Exhibit 10.2.What number of observations is classified correctly?

One element in cleaning the data set in the mining process involves

Exhibit 10.1 The following questions are based on the problem description,regression results,and the Analytic Solver Platform Discriminant Analysis report below. A college admissions officer wants to evaluate graduate school applicants based on their GMAT scores,verbal and quantitative.Students are classified as either successful or not-successful in their graduate studies.The officer has data on 20 current students,ten of whom are doing very well Group 1)and ten who are not Group 2). Unpooled Estimates of within-group Covariance matrices are used,assuming they are different. Group Centroids Group Quantitative Verbal 1 683.8 654.2 2 610.7 605.7 $\text { Classitication Matrix }$ Actual / Predicted Group1 Group2 Total \% correct Group1 9 1 1 90.00\% 0 Group2 2 8 1 80.00\% 0 Total 1 9 2 85.00\% 1 0 -Refer to Exhibit 10.1.What is the verbal test score value of the group centroid for group 2?

Exhibit 10.1 The following questions are based on the problem description,regression results,and the Analytic Solver Platform Discriminant Analysis report below. A college admissions officer wants to evaluate graduate school applicants based on their GMAT scores,verbal and quantitative.Students are classified as either successful or not-successful in their graduate studies.The officer has data on 20 current students,ten of whom are doing very well Group 1)and ten who are not Group 2). Unpooled Estimates of within-group Covariance matrices are used,assuming they are different. Group Centroids Group Quantitative Verbal 1 683.8 654.2 2 610.7 605.7 $\text { Classitication Matrix }$ Actual / Predicted Group1 Group2 Total \% correct Group1 9 1 1 90.00\% 0 Group2 2 8 1 80.00\% 0 Total 1 9 2 85.00\% 1 0 -Refer to Exhibit 10.1.Suppose that for a given observation,the difference between Mahalanobis distances between group 1 and 2 G1-G2)is big and negative.This means that

the k-means clustering algorithm is available

A graphical representation of a set of rules for classifying observations into 2 or more groups is called

Exhibit 10.1 The following questions are based on the problem description,regression results,and the Analytic Solver Platform Discriminant Analysis report below. A college admissions officer wants to evaluate graduate school applicants based on their GMAT scores,verbal and quantitative.Students are classified as either successful or not-successful in their graduate studies.The officer has data on 20 current students,ten of whom are doing very well Group 1)and ten who are not Group 2). Unpooled Estimates of within-group Covariance matrices are used,assuming they are different. Group Centroids Group Quantitative Verbal 1 683.8 654.2 2 610.7 605.7 $\text { Classitication Matrix }$ Actual / Predicted Group1 Group2 Total \% correct Group1 9 1 1 90.00\% 0 Group2 2 8 1 80.00\% 0 Total 1 9 2 85.00\% 1 0 -Refer to Exhibit 10.1.Based on the regression output,what is the discriminant score for a student with a quantitative score of 635 and a verbal score of 570?

Standardization of a variable

The first step in creating a classification tree involves