Java Reference

In-Depth Information

Let us say there are two attrition models,
Model A
and
Model B
,

that are built using different algorithms or with different settings

using the same algorithm. Figure 7-8 illustrates the cumulative lift

and cumulative gains charts plotted for these models to compare the

results. Note that Model A outperforms Model B in the first two

quantiles; however, Model B outperforms from the third quantile

onward. A user can pick Model A when the budget allows for at

most 20 percent of customers, otherwise the user can pick Model B if

more than 20 percent of customers are budgeted.

7.1.7

Apply Model: Obtain Prediction Results

After evaluating model performance using the test data, the user

selects the best model for the problem and applies it to predict target

values for an apply dataset. As noted for decision tree, some algorithms

may use a subset of the input attributes in the final model. This sub-

set of attributes is called the
model signature
, and it can be retrieved

from the model to determine which attributes are required to apply

the model.

In this section, we take the simple decision tree model discussed

in Section 7.1.5 to illustrate the model apply operation. This model

has three input attributes:
age, capital gain, and average savings balance

as shown in Table 7-3 and the model uses only two of these,
age
and

average savings balance
, as shown in Figure 7-9. These two attributes

form the model signature. Consequently, to use this model, the

apply dataset for this model needs only contain cases with
age
and

average savings
balance
attribute values. Consider an apply dataset

that has two customer cases for customers Jones and Smith as shown

in Table 7-6 to understand the apply process.

Figure 7-9 illustrates how the decision tree model predicts if these

customers are attriters.
Jones
is older than 36, so from the root node

he is assigned to node-2 that predicts him as an
attriter
.
Smith
is

younger than 36, so he is assigned to node-3 and node-3 further splits

Table 7-6

Customer apply table

Customer

name

Average saving

account balance

Id

Address

City

State

Zip code

Age

A1

Jones

10 Main St.

Boston

MA

02101

41

$11,500

A2

Smith

120 Beacon St.

Buffalo

NY

14201

35

$3000

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