 was observed, we can compare them!

---
class: middle, center, frame

# Axiom

Better Model = Better Predictions (Lower error rate)

---
template: lm-predict

---
class: middle, center

# Residuals

&lt;img src="figs/01-Predicting/lm-resid-1.png" width="504" style="display: block; margin: auto;" /&gt;


---
class: middle, center

# Residuals

The difference between the predicted and observed values.

$$ \hat{y}_i - {y}_i$$ 

???

refers to a single residual. Since residuals are errors, the sum of the error