I’m trying to understand how to interpret the return values, specifically “Coefficients:”, of R’s lm function. I’m using it with a dichotomic predictor (mom_hs).
lm(data$kid_score ~ data$mom_hs) returns Coefficients: # (Intercept) data$mom_hs # 77.55 11.77 I read that the (Intercept) value is the “y-intercept” value b, i.e. the y value where the line intercept the y-axis. The second value is the value of the term m (or “slope”) in the equation of a line y=mx+b. However, These two numbers also have the following interpretations: b or (Intercept) value is the same as: The mean of those data$kid_score that have data$mom_hs == 0. Why is this a valid interpretation? m or data$mom_hs value is the same as: The difference of means between those data$kid_score that have data$mom_hs == 1 and those data$kid_score that have data$mom_hs == 0. Why is this a valid interpretation? Can someone explain? ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
