Posted by
researcher on
Mar 15, 2014; 2:32pm
URL: http://spssx-discussion.165.s1.nabble.com/best-test-for-this-analyses-tp5724913p5724914.html
Ps just to say that I think I can use wilcoxon for testing whether
performance differs significantly between biology and english and I guess I
can do that per year or all years combined.
---
I would be greatful for advice on analysing this data in SPSS
A study was done of comparing test results (% correct responses) on two
subjects biology and english. The tests are supposedly adjusted so as to be
of equal difficulty (approx).
The study was done in 3 years of a school at the same time.
So we have 33 subjects in year 1 tested on biology and english (the same
participants were tested twice, once in each subject - i.e. repeated
measures) from year 1, same for year 2, same for year 3 (total 99
participants)
SO the research question is whether there are differences on the basis of
subject (i.e. do scores on biology differ significantly from those on
english) and whether performance improves over the years (i.e. is year 2
better than year 1, is year 3 better than year 2).
I was thinking ANOVA with multiple comparison tests. Problem is that
normality tests show not normal distribution (KS And SW)
so then thinking kruskall wallis but the assumption of the variables having
the same shaped distribution is not met (one has a positive skew the other
negative).
I ran the kruskall wallis test anyway and it showed significant differences
by year for one of the subjects (english)but not for the other (biology).
Even of I could use KW this still leaves the issue of how to do multiple
comparison test with non parametric data, to find out which years differ
from which. Reading suggests this is obscure process with non parametric
data?
Then there is the other research question - hoe to test for significant
differences on basis of subject?
Think I need to give this more thought bit any guidance much appreciated
Thanks
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