Multiple Linear Regression Results Table (from Hofferth, S. L. (2006) Residential father family type and child well-being: investment versus selection. Demography, 43(1), pages 53-77) Take Home Message If a coefficient is negative, then more of that covariate leads to less of the outcome variable (holding the values of the other covariates constant) If a coefficient is positive, then more of that covariate leads to more of the outcome variable (holding the values of the other covariates constant) The p-value gives the probability of getting that coefficient value in your sample ASSUMING that the coefficient in the population is 0. The coefficient in the population is (almost) never 0. Do NOT use p-values to decide on the importance of a covariate (i.e. the size of its effect). The p-value does not necessarily reflect the importance of a covariate. It reflects measurement error and sample size. The importance of a covariate (e.g., whether it has a small, medium, or large effect) is a judgment made by the researcher. Consider using standardized regression coefficients Logistic Regression Results Table (from Eloundou-Enyegue, P. M. & Williams, L. B. (2006) Family size and schooling in sub-Saharan African settings: A reexamination. Demography, 43(1), pages 25-52) Note that Exp(B) is the odds ratio. Take Home Message If a coefficient is negative the odds ratio is less than 1, then more of that covariate makes the outcome less likely (holding the values of the other covariates constant). If a coefficient is positive the odds ratio is more than 1, then more of that covariate makes the outcome more likely (holding the values of the other covariates constant). The p-value gives the probability of getting that coefficient value (and corresponding odds ratio) in your sample ASSUMING that the coefficient in the population is 0. The coefficient in the population is (almost) never 0. Do NOT use p-values to decide on the importance of a covariate (i.e. the size of its effect). The p-value does not necessarily reflect the importance of a covariate. It reflects measurement error and sample size. The importance of a covariate (e.g., whether it has a small, medium, or large effect) is a judgment made by the researcher. The purpose of this class is to convince you to display your results in terms of predicted probabilities and to show you how to do this.