This list is about R programming. Yours is a statistical question. Although there is certainly a nonempty intersection (and someone may attempt a response), statistical questions are better directed to a statistical list like stats.stackexchange.com.
Cheers, Bert Bert Gunter "Data is not information. Information is not knowledge. And knowledge is certainly not wisdom." -- Clifford Stoll On Mon, Nov 23, 2015 at 3:58 PM, angelo.arc...@virgilio.it <angelo.arc...@virgilio.it> wrote: > Dear list members, > I have to perform the following analysis but I do not know which function in R > must be used. My guess is to use manova(). > > During an experiment I presented participants with some sound stimuli and I > asked them to > modify two parameters of the sound (Centroid and Sound_Level_Peak) to reach a > given > experimental goal. The initial sounds (preset sounds) had a value for those > two parameters. > What I am interested in is whether participants' modifications of the two > parameters of the > sound stimuli resulted in values actually different from the initial values > of the parameters > of the preset sounds. > > To give an idea, some rows of my data set are the following: > >> head(scrd) > Stimulus_Type Centroid Sound_Level_Peak Preset > Stimulus_A 1960.2 -20.963 no > Stimulus_A 5317.2 -42.741 no > ..... > Stimulus_B 11256.0 -16.480 no > Stimulus_B 9560.3 -19.682 no > ..... > ..... > Stimulus_A 1900.2 -18.63 yes > Stimulus_A 5617.6 -44.41 yes > Stimulus_B 12056.0 -17.80 yes > Stimulus_B 8960.5 -21.82 yes > > > This is the analysis I performed with manova(): > >> fit <- manova(cbind(Centroid,Sound_Level_Peak)~ Stimulus_Type*Preset, >> data=scrd) >> summary(fit, test="Pillai") > Df Pillai approx F num Df den Df Pr(>F) > Stimulus_Type 11 0.91888 106.629 22 2760 < 2e-16 *** > Preset 1 0.00343 2.371 2 1379 0.09378 . > Stimulus_Type:Preset 11 0.01155 0.729 22 2760 0.81348 > Residuals 1380 > --- > Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 >> > > If I am not wrong, these results say that for each stimulus type there is no > difference > between the patterns of the two parameters in the preset and modified > conditions. > > Can anyone please tell me if I am correct or suggest how to perform in R such > an analysis? > > Thanks in advance > > Best > > Angelo > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. ______________________________________________ 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.
