I conducted listening experiment in which 16 participants had to rate the audio stimuli along 5 scales representing an emotion (sad, tender, neutral, happy and aggressive). Each audio stimulus was synthesized in order to represent a particular emotion. Participants had to move 5 sliders each of which corresponded to one of the 5 emotions.
The sliders range was [0,10] but participants were only informed about the extremities of the sliders (not at all - very much). There was not a force choice, therefore potentially each audio stimulus could be rated with all the scales (e.g. sad = 0.1, tender = 2.5, neutral = 2., happy = 8.3, aggressive = 1.7).
There were 40 stimuli, each stimulus was repeated twice, for a total of 80 trials.
To analyze the data I want to use a MANOVA with repeated measures (in R). For this purpose I use the audio stimulus as independent variable having 40 levels, while the 5 responses as dependent variables. Since each individual has been measured twice, I include a within-subjects factor for trial number.
I want to demonstrate that the created stimuli were actually correctly classified in the corresponding emotion. For example I expect that happy sounds result in happy ratings by participants and that these happy ratings are greater than the other 4 responses.
I studied the R documentation and examples, but I encountered the following error while adapting those examples to my case:
model.emotions<-lm(cbind(Sad,Tender,Neutral,Happy,Aggressive) ~ Trial,data=scrd) idata<-data.frame(scrd$Trial_number) aov.emotions<-anova(model.emotions,idata=idata, idesign=~Trial, type="III") > aov.emotions<-anova(model.emotions,idata=idata, idesign=~Trial, type="III") Error in cbind(M, X) : number of rows of matrices must match (see arg 2)
I am not fully sure of the above formula, since I am not an expert in R. Can you please correct them showing the correct R code?
The .csv table with all the data can be downloaded here: https://dl.dropbox.com/u/3288659/Results_data_listening_Test.csv
In addition I was not able to find any post hoc test to apply to the result of the MANOVA in case of a significant main effect. Any suggestion?
Thanks in advance