Hi Sara, As the help page for anova.lm says, "Specifying a single object gives a sequential analysis of variance table".
That most likely also the answer to your second question. The anova function can be used to compare nested models, and this provides the flexibility to test arbitrary hypotheses, including all the ones given by different "types" of ANOVA tables. You may also find the Anova() function in the car package helpful. Best, Ista On Thu, May 12, 2011 at 2:37 AM, Sara Sjöstedt de Luna <sara.de.l...@math.umu.se> wrote: > Hi! > > We have run a linear regression model with 3 explanatory variables and get > the output below. > Does anyone know what type of test the anova model below does and why we get > so different result in terms of significant variables by the two tables? > > Thanks! > > /Sara > >> summary(model) > Call: > lm(formula = log(HOBU) ~ Vole1 + Volelag + Year) > Residuals: > Min 1Q Median 3Q Max > -0.757284 -0.166681 0.009478 0.181304 0.692916 > Coefficients: > Estimate Std. Error t value Pr(>|t|) > (Intercept) 80.041737 12.018726 6.660 1.40e-07 *** > Vole1 0.005521 0.041626 0.133 0.8953 > Volelag 0.033966 0.018392 1.847 0.0738 . > Year -0.035927 0.006027 -5.961 1.08e-06 *** > > anova(model) > Analysis of Variance Table > Response: log(HOBU) > Df Sum Sq Mean Sq F value Pr(>F) > Vole1 1 1.7877 1.7877 13.1772 0.0009486 *** > Volelag 1 0.5817 0.5817 4.2878 0.0462831 * > Year 1 4.8205 4.8205 35.5323 1.082e-06 *** > Residuals 33 4.4769 0.1357 > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > 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. > -- Ista Zahn Graduate student University of Rochester Department of Clinical and Social Psychology http://yourpsyche.org ______________________________________________ R-help@r-project.org mailing list 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.
