Re: Separate One-Way vs Two-Way Repeated Measures
Posted by
Alex Reutter on
Apr 29, 2015; 1:42pm
URL: http://spssx-discussion.165.s1.nabble.com/Separate-One-Way-vs-Two-Way-Repeated-Measures-tp5729421p5729422.html
Hi João,
You want to look at linear mixed models
to deal with the non-existent combinations:
http://www-01.ibm.com/support/knowledgecenter/SSLVMB_22.0.0/com.ibm.spss.statistics.help/spss/advanced/idh_mixl.htm
http://www-01.ibm.com/support/knowledgecenter/SSLVMB_22.0.0/com.ibm.spss.statistics.reference/spss/advanced/syn_mixed.htm
http://www-01.ibm.com/support/knowledgecenter/SSLVMB_22.0.0/com.ibm.spss.statistics.cs/spss/tutorials/mixed_table.htm
Alex
From:
João Guerreiro <[hidden email]>
To:
[hidden email]
Date:
04/29/2015 06:50 AM
Subject:
Separate One-Way
vs Two-Way Repeated Measures
Sent by:
"SPSSX(r)
Discussion" <[hidden email]>
Hello everyone,
I'm struggling with a Within-Subjects analysis and I haven't found the
answer to my doubts, so here it goes:
I have two IV (Time and Voice Conditions) and one DV (continuous variable).
Time conditions depend on the Time to Complete the task
Voice conditions refer to different voices used
Time Condition
1
2 3
4 5
6
1 x
x x
x
Voice Conditions 2
x x
x x
x x
3
x x
x x
x
This table shows all combinations Time X Voice that were tested, by all
participants (30). For example, Time condition 1 with Voice condition 3
was not executed by any participant.
What I want with this test is to obtain the following comparisons:
- Within each Time Condition, check for differences in Voice conditions
- For each voice condition, check for differences in time condition (in
particular, I want to know when does performance start to deteriorate significantly).
My first thoughts were to perform one-way repeated measures ANOVA (or Friedman
due to normality violation) within each time condition; and then within
each voice condition (Followed by post-hocs).
However, I found that I could analyze these two variables together with
the two-way repeated measures ANOVA. I performed this analysis using the
General Linear Model -> Repeated Measures menu. Yet, I found the following
problems:
- I have a few combinations that don't exist (for example Time 1 X Voice
3); If I use empty values, I get no results for all the analysis... but
I have to insert one variable in order to proceed with the analysis. What
should I do?
- When checking for normality, almost all TimeXVoice conditions violate
the assumption. I read that normality is not that strict in this test,
but some of the conditions show Sig results of ,000 and almost all of them
are below ,050. Should I go for a non-parametric alternative?
Is it OK to use the one-way version and analyze each of the variables separately
or should I do the two-way analysis? How should I overcome the problems
referred above? Should I consider a different test?
I hope I have provided enough details.
Thanks in advance,
--
João Guerreiro
- Researcher @ INESC-ID / Visualization and Intelligent MultiModal
Interfaces Group
- PhD Student @ IST / Technical University of Lisbon
- Tel: +351.21.4233532
- web: http://web.ist.utl.pt/joao.p.guerreiro/
===================== To manage your subscription to SPSSX-L,
send a message to LISTSERV@...
(not to SPSSX-L), with no body text except the command. To leave the list,
send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions,
send the command INFO REFCARD
=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD