STATISTIK-FORUM.de

[eva9]

I have conducted a language acquisition study for an article with two groups using the same test sentences. First I made them do an independent English test to categorize the students into 3 levels (low-mid-high) of proficiency.
There were 3 types of sentences, 8 test sentences for each type. Then I conducted a factorial ANOVA for both groups, the 3 levels as between subject factor and type of sentences as within subjects factor (3) in order to see if there are significant differences among their correct production of the three types.
Now the reviewer tells me that I should match the proficiency level of the two groups to be shown by statistics in order to be able to talk about their production (make sure that both groups are at comparable levels of proficiency in English). HOW?
Intuitively, I ran SPSS GLM Repeated measures on the low (also mid and high separately) level data for both groups: type of sentence (within-subj), study (1&2) (between subj), test results (points quasi continuous 1-50) as covariate.
Could somebody help me if it is right and tell me how to interpret the result? (it was easier to write in English but I can communicate in German as well)