Feb 4, 2015
my data set consists of the questionnaire responses of several hundred teachers.
about one third are elementary, middle school, and secondary
they each rated the importance of 15 items on a scale of 0-3
i am comfortable treating these ratings as interval level data, or ordinal is OK if that works
i have no interest in main effects: the items do not go together; each is stand-alone, so total score is of no interest
also, combining any item's scores across groups makes no sense either
instead, my questions are these:
1-for the group of elementary teachers, which of the 15 items are rated significantly higher than others?
2- same for middle school teachers
3- same for high school teachers
4-does one of the 3 teacher groups rate item 1 significantly different than the other two groups?
5- same for items 2—15
i realize i am going to have to slice up alpha pretty thin
my first thought was ANOVA for repeated measures with followup tests, and just ignore the main effects to get to the followup tests.
but the Mauchly’s sphericity test was significant, seemingly indicating the need for a MANOVA with followup tests (?)
How do I do followup mean comparisons after a MANOVA in JMP?
I still want to answer questions 1 through 5 above
alternatively, should I be looking at a different analysis, since I am uninterested in the main effects?