Hi everyone, I have some troubles understanding some result of my Kruskal-Wallis test:
I want to compare a variable across these 3 independent groups, and since its distribution is not normal, I run a non-parametric test. The test tells me to reject the null hypothesis (p=.000). The mean rank for each group is as follow: Gr1= 70.68; Gr2= 84.76; Gr3= 52.31
From the pairwise comparison, looking at the adjusted significance values, I see that Group 2 and 3 are significantly different (p=.000), while Group 1 and 3 (p=.078) and Group 1 and 2 (p.=.274) are not significantly different. But in the Homogeneous Sbubset table each group is placed under a different subset.
My questions are :
-Why are the two follow-up analyses giving me a different result? Which one do I trust?
-Am I doing right comparing the adjusted significance value with the "usual" .05 alpha, or should I compare it with an adjusted alpha of .0167 ?
-How do I interpret the fact that Gr 1 (the "middle one" in terms of mean rank) is not different from the other two groups, but gr2 and gr3 are different? (this is more a general question because a similar thing is happening in another analysis I run).
I hope everything is clear, I apologize if some terminology is not correct, it's my first time working with SPSS. Thank you for your time in advance
I want to compare a variable across these 3 independent groups, and since its distribution is not normal, I run a non-parametric test. The test tells me to reject the null hypothesis (p=.000). The mean rank for each group is as follow: Gr1= 70.68; Gr2= 84.76; Gr3= 52.31
From the pairwise comparison, looking at the adjusted significance values, I see that Group 2 and 3 are significantly different (p=.000), while Group 1 and 3 (p=.078) and Group 1 and 2 (p.=.274) are not significantly different. But in the Homogeneous Sbubset table each group is placed under a different subset.
My questions are :
-Why are the two follow-up analyses giving me a different result? Which one do I trust?
-Am I doing right comparing the adjusted significance value with the "usual" .05 alpha, or should I compare it with an adjusted alpha of .0167 ?
-How do I interpret the fact that Gr 1 (the "middle one" in terms of mean rank) is not different from the other two groups, but gr2 and gr3 are different? (this is more a general question because a similar thing is happening in another analysis I run).
I hope everything is clear, I apologize if some terminology is not correct, it's my first time working with SPSS. Thank you for your time in advance