I am a French student in psychology and I am currently using spss to analyze my research project's results.
I work on the perception of dyslexic and non dyslexic secondary school students. I used spss to analyze the differences to a questionnaire (likert scale) between a group of dyslexic pupils and a group of non dyslexic pupils. I did the same to analyze the differences between girls and boys and between four age groups. I think I manage to do and analyze it quite ok.
Now I would like to check the differences with all the independent variables (dys/non dys, sex and age). To do so, I did a multivariate general linear model and obtained the document attached. Being inexperienced in statistics, I don't really know how to interpret these results since it is quite a complex test.
I also don't understand some results. If I take a look at the tests of between subjects effects, I can see that for the "groupeage", there are some significant differences for 6 questions (1, 18, 20, 28, 29, 44).But when I did a general linear model with just the age group as an independent variable (dependent variable being always the answers to the questionnaire questions), I only get significant differences for 3 questions (1, 20,29). I don't understand why there are differences between the two tests and it does the same using "sex" as the independent variable.
To sum up I have two questions :
- how should I interpret the results of the multivariate general linear model (and especially the interactions of the IVs and their effect on the DVs)?
- Why there are some differences in the results between the multivariate general linear model and the other documents centered only on one VI (age or sex)?
I hope my explanation was clear enough and in order to get it clearer, all the documents I talked about can be downloaded on those links I try to attach them to this message but I wouldn’t work) :
I really thank you for all the help you could provide me