STAT 1400 Lecture Notes - Lecture 14: Null Hypothesis, Epistasis
Document Summary
A significant p-value suggests that the data do not follow that model. But finding a non-significant p-value is not a validation of the null hypothesis and does not suggest that the data do follow the hypothesized model. It only shows that the data are not inconsistent with the model. Example: under a genetic model of dominant epistasis, a cross of white and yellow summer squash will yield white, yellow, and green squash with probabilities 12/16, 3/16 and 1/16 respectively (expected ratios 12:3:1). H0: pwhite = 12/16; pyellow = 3/16; pgreen = 1/16. We use h0 to compute the expected counts for each squash type. Degrees of freedom = k 1 = 2, and x2 = 0. 691. Using table d we find p > 0. 25. This is not significant and we fail to reject h0. The observed data are consistent with a dominant epistatic genetic model (12:3:1). Example: the frizzle fowl is a chicken with curled feathers.
