Participants and items as random factors

Moderators: statman, Analyst Techy, andris, Fierce, GerineL, Smash

Posts: 1
Joined: Mon Feb 16, 2015 11:55 pm

Participants and items as random factors

Postby asudar » Tue Feb 17, 2015 12:05 am

Im trying to run ANOVA with SOA (4 levels) and Age (2 levels) as the between subject factor and Interfering Stimuli (4 levels) as the within participant factor. How do I include participants and items as random factors? Im confused as to how to arrange the data in SPSS. My Dependent variable is Reaction time, Independent variables are Age, SOA and Interfering Stimuli
Here is a snippet of how Im organising data in the data view column of SPSS.
Age (categorical variable;column1).......SOA (categorical variable; column 2).......IS (categorical variable; column 3)..... Reactiontime (continuous variable; column 4)

Thanks in advance for your help.
Posts: 25
Joined: Tue Feb 24, 2015 11:58 pm

Re: Participants and items as random factors

Postby iopsych » Sun Mar 01, 2015 11:51 pm

Hello Asudar,

First, your formatting of the data is not appropriate for such an analysis. You need to create a separate variable for each level of your within-subjects (WS) factor. So you would have Age (categorical variable;column1).......SOA (categorical variable; column 2).......IS1 (nominal vaiable; column 3)..... IS2 (nominal vaiable; column 4).......IS3 (nominal vaiable; column 5)........IS4 (nominal vaiable; column 6)........Reactiontime (continuous variable; column 7).

Regarding how you can run the analysis; use the "Analyze-General Linear Model-Repeated Measures" path to access the diologue box to run the analysis. When you click on it, you will first need to type in your WS factor (IS) and how many levels it has (4). Then, in appropriate order, define each level of your WS factor. After this is done, choose your BS factors and you are all set.

I hope this was helpful.


Who is online

Users browsing this forum: No registered users and 5 guests