* sums of squares, cochran's theorem

* SS decomposition

* F tests

* Maybe LRT's

* Interactions in general (2-way, maybe 3-way)

* Dummies, baseline categories & the intercept, sum-to-zero
  constraints

* ANOVA as lm

* interactions with dummies

* ANCOVA and the standard tests and pictures

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HW: prove sum e_i= 0 using matrix algebra