Page 353 - Special Topic Session (STS) - Volume 2

STS498 Wei-Yin L.

Figure 1: GUIDE piecewise constant least-squares regression tree for predicting
INTRDVX. At each split, an observation goes to the left branch if and only if the
condition is satisfied. The symbol ‘<∗’ stands for ‘< or missing’. Sample size (in italics)
and mean of INTRDVX printed below nodes.

3. Crash test data
The data come from 15,941 crash tests of vehicles involving test dummies
done between 1972 and 2004 by the National Highway Transportation Safety
Administration (ftp://www.nutsa.dot.gov/ges). Each record consists of
measurements from the crash of a vehicle into a fixed barrier. One variable is
HIC, the amount of head injury sustained by a test dummy seated in the
vehicle. For our purpose here, we define Y = 1 if HIC exceeds 1000, and Y = 0
otherwise. Thus Y indicates when severe head injury occurs. We use 109

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