Overview of JoniGuerrero on PostgraduateForum.com

Overview of JoniGuerrero

Signup date: 12 Sep 2011 at 9:12am

Last login: 12 Sep 2011 at 9:12am

Post count: 10

Recent Posts

Statistical tests - Within-subjects for categorical data

JoniGuerrero 10 posts
13 years ago

Quote From skig:

I'm not best at stats but I'm confused about your variables. Are you trying to predict something? Or just comparing four variables? I think you can use chi-square if you're comparing yes... but with 23 participants and the number of variables I'm not sure the power will be that great to be honest.

Yes I am comparing. I've found something that seems very similar to what I want, but that only allow 2 categories (for yes/no variables). That's the Cochran Q test. If it would allow more than 2 categories I guess it would be it...

Statistical tests - Within-subjects for categorical data

JoniGuerrero 10 posts
13 years ago

Quote From sneaks:

yeah you can use chi-square for categorical data like that, although maybe you could use logistic regression, using your 4 conditions as predictors and having a dichotomous outcome where ou collapse the first two answers (i.e. not mentioned) as 0 and the last two (i.e. mentioned) to 1. But that would depend on your study. and with just 23 participants you don't really have the power so chi-square is probably your best bet.

I also thought about using chi-square, but is that suitable for within-subjects/repeated-measures? I read that one of the assumptions is independent observations (each person or case can be counted only once)

Statistical tests - Within-subjects for categorical data

JoniGuerrero 10 posts
13 years ago

It has 4 different conditions (the repeated measures part).
Besides that, the dependent variable is categorical. I'll say the possible values to better comprehension:
0- Did not mention
1- Did not know
2- Mentioned Induced
3- Mentioned Spontaneously

Since the variable is categorical instead of continuous, I think it is incorrect to use the ANOVA. I guess I could use the Friedman Test (the non-parametric for the repeated measures ANOVA) if I consider the variable ordinal; however, I think it is more correct to consider it nominal instead.

Statistical tests - Within-subjects for categorical data

JoniGuerrero 10 posts
13 years ago

Thank you for your answer. I think ANOVA can only be used for continuous data, and my dependent variable is categorical instead. Am I right?

Thanks

Statistical tests - Within-subjects for categorical data

JoniGuerrero 10 posts
13 years ago

Hello, I am struggling to find a suitable statistic test for one of my studies... and hope that anyone can help me with it:
I have 4 different conditions, and I want to test if my results differ on those conditions. When the dependent variable is continuous it is easy to find a statistical test, however when it is a categorical variable I am not finding the right one.

Some details that may help:
Number of users: 23
Categorical Variable: 4 different values (not ordinal.. but can be ordinal if that's the only way)

Any suggestions?

Thanks for the help in advance,
João Guerreiro