7.6 Omnibus tests for “Goodness of Fit”
The summary output for a linear model includes key elements from the ANOVA table for the omnibus statistical tests that assess goodness of fit. Let’s look at it again here.
summary(lin.model)
##
## Call:
## lm(formula = Y.2016 ~ Y.2012, data = election50)
##
## Residuals:
## Min 1Q Median 3Q Max
## -0.079300 -0.022713 0.000465 0.019404 0.061641
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -0.02235 0.02148 -1.041 0.303
## Y.2012 0.95295 0.04364 21.838 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 0.03152 on 48 degrees of freedom
## Multiple R-squared: 0.9086, Adjusted R-squared: 0.9066
## F-statistic: 476.9 on 1 and 48 DF, p-value: < 2.2e-16
- What are the ANOVA table test components shown here?
- Interpret the values of \(R^2\) and the \(F\)-statistic. What do they say about the goodness of fit?