Tukey-Anscombe Plot
A Tukey-Anscombe plot, more commonly known as a residuals vs. fitted plot is a visualization technique for evaluating the fit of a model.
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Description
A model can almost always be fit to a set of observations; the question remains as to whether the model is a good fit. By plotting the observed dependent variable against the model's residuals, trends that might indicate poor fit become apparent.
- A trend in the residuals, like a curve, suggests that the true relationship is not linear.
- Widening or thinning of the dispersion of residuals suggests that the variance of the error term is not constant.
- Outliers are clearly visualized.