Chapter 7
Some
Regression
Pitfalls
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Section 7.1
Introduction
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Section 7.2
Observational
Data versus
Designed
Experiments
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Section 7.3
Parameter
Estimability
and
Interpretation
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Figure 7.1 Creativity and flexibility
data for three children
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Figure 7.2 Only two different x-values
observed - the second-order model is not
estimable
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Figure 7.3 SAS output for
interaction model, Example 7.3
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Figure 7.4 SPSS regression
printout for grandfather clock model
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Section 7.4
Multicollinearity
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Figure 7.5 SAS regression printout
for FTC model
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Figure 7.6 SAS correlation matrix for
independent variables in FTC model
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Section 7.5
Extrapolation:
Predicting
Outside the
Experimental
Region
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Figure 7.7 Using a regression model
outside the experimental region
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Figure 7.8 Experimental region for
modeling GDP (y) as a function of inflation
rate (x1) and prime interest rate (x2)
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Figure 7.9 MINITAB descriptive statistics
for independent variables, Example 7.6
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Section 7.6
Variable
Transformations
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Figure 7.10 Hypothetical relation
between demand y and price p
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Figure 7.11a,b,c&d Graphs of some
mathematical functions relating E(y) to p
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Figure 7.11e,f&g Graphs of some
mathematical functions relating E(y) to p
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