Re: [R] Comparing regression models

2007-09-14 Thread Lucke, Joseph F
The classic way to test for better fit with an additional variable is to use the anova() function. The model must have the suspect variable listed last into your model. The anova() function will give you the correct sequential decomposition of your model effects and their conditional (F or t)

Re: [R] Comparing regression models

2007-09-14 Thread Wayne.W.Jones
I would suggest doing an F-test.A descrition is given here: http://www.graphpad.com/curvefit/2_models__1_dataset.htm. The method is valid becasue one of your models is a subset of another. Correct use of the anova function does indeed perform this test. For example: data(airquality) lm1<-l