Anova does analysis of variance: this is a hypothesis test that evaluates the signiicance of mean diferences, used for hypothesis tesing in: It evaluates the likelihood that proporions of variance we observe could occur by chance. Want to know if the mean diferences found in the same can also be found true for the mean diferences found in the populaion. Compare diferences between samples (numerators) with diferences that would be expected from chance factors like experimental error (denonminator) If both, numerator is larger than denominator, so there is a signiicant diference between treatments. Numerator measures actual diference in mean (source) Denominator measures diference expected if no efect. T test is based on distance between the means: though the t test does use variability in it"s denominator there is no variability raio the raio has two types of variability, based on sample mean diference. Anova is based on variability in denominator.