Question

Table 3.5. Data set for Exercise 2 Customer ID Gender Car Type Shirt Size Class amily Sports Sports Sports SportsExtra LargeC Sports Extra LargeC Sports Sports Sports Luxury Family Family Extra Large Cl Family LuxuryExtra LargeC1 Luxury Luxury Luxury Luxury Luxury Luxury Medium Medium Large CO CO Small Small Medium Large Large CO CO C1 10 12 13 14 Medium C1 16 17 18 19 20 Small Small Medium Medium Medium Large C1 C1 C1 C1 C1 C1

Consider the training examples shown above in Table 3.5 for a binary classification
problem.
(a) Compute the Gini index for the overall collection of training examples.
(b) Compute the Gini index for the Customer ID attribute.
(c) Compute the Gini index for the Gender attribute.

Answer 1

AnseY a) 6INI INDEX f ovevall collection Traiving example The Gin index s mne Ihe sum o the fraction ot Ye cordi belonging Xo . at- a given node GinipclasCcr/clas) 2.0)- The cutromeYTD makes仆co That we have· 20 Gini alue」

Gini Cusromey 1o) hoO4 20 e) Gini Index fov Giender atvilade e 0. 48 Gini (Female): t-rCol) PCC,旧 : 48 Gini (Gerde).TConale). ..|*G: endey)- T Cfema le) T (Temote+ ma Sini Female : O.49