![]() ![]() ![]() Alternatively, if you meant including the multiple subscales in the MANCOVA (not repeated measures), I might have some concerns about that, because of how the partial estimates would impact your results (each effect would control for the pre-test for all subscales).ģ) I think using a bonferroni is a reasonable strategy for testing multiple subscales, yes. HOWEVER, if previous literature would suggest that additional variables are likely influential on your DV, and may confound results, then it would be advisable to hold those variables constant also.Ģ) I'm not sure I understand this question: if you are running a MANCOVA then don't you have both the pretest and posttest as DVs (repeated measures)? If so, then it can't be included as a covariate. If what you want to know is simply the difference between groups, holding pre-test scores constant then an ANCOVA (as you've described) is fine. Thanks for any advice you can provide! Hilaryġ) I'm afraid I can't tell you if it is "OK" to do that or not, because it is a conceptual questions/issue that you must determine based on what you'd expect from previous literature. My sample will be divided into groups by autism diagnosis: no diagnosis/typically developing, autism, PDD-NOS I am essentially asking four questions: * Does nonverbal communication/socialization affect anxiety, depression, and/or somatization? * Does verbal communication affect anxiety, depression, and/or somatization? * Do social relationships affect anxiety, depression, and/or somatization? * Does insistence on sameness/restricted interest affect anxiety, depression, and/or somatization? I am wondering if each question should be a separate test or if it would be better/possible to combine them all in one statistical analysis, like a MANCOVA. I am looking at what autism symptoms (based on scores on a measure: a total score and 4 subscale scores) may predict internalizing problems (based on scores on a different measure: a total score and 3 subscale scores). I'm hoping you can help me here as I am a bit stumped. Hi Jeremy, I've read your description of a MANCOVA and am unsure if it would apply to my study. Query 4: What post hoc tests (in SPSS) can be used in this case? Query 3: Is it ok if ANCOVA is conducted on each sublevel of each dependent variable with pre-test measures as covariates, by adopting Bonferroni method for controlling the type I error rates? Query 2: Is it ok if MANCOVA is conducted on each dependent variable with pre-test measures as covariates to detect any significant differences among the 3 groups?(MANCOVA because sublevels/subscales of each dependent variable are correlated with each other) Query 1: If the 3 groups are found to be equivalent at pre-test stage (either quasi or true experimental method is used), is it ok to go for ANCOVA using pre-test measures as covariates or is there a need to include intelligence or other relevant variables as covariates? three dependent variables: (a) achievement (3 sublevels-knowledge, comprehension, application) (b) attitude (measured by likert scale having 5 subscales) (c) attitude (measured by likert scale having 5 subscales) ![]() two independent variables: (a) teaching methods (3 levels/groups) (b) genderĢ. In a pre-post test experimental study having 3x2 factorial design, there are:ġ. ![]()
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