Login  Register

Re: repeated measures custom contrasts for linear trends

Posted by statisticsdoc on Feb 05, 2007; 2:08pm
URL: http://spssx-discussion.165.s1.nabble.com/repeated-measures-custom-contrasts-for-linear-trends-tp1073671p1073676.html

Paul,

Replace Polynomial with Special in the WSFACTOR line, and supply a set of
contrasts that you specify.  Since you have a significant cubic interaction,
you should consider more than just the linear trend.  Testing just the
linear trend might be misleading if there are cubic or other higher order
effects.

HTH,

Stephen Brand

For personalized and professional consultation in statistics and research
design, visit
www.statisticsdoc.com


-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]]On Behalf Of
Paul Mcgeoghan
Sent: Monday, February 05, 2007 8:27 AM
To: [hidden email]
Subject: Re: repeated measures custom contrasts for linear trends


Stephen,

The Tests of Within-Subjects effects Greenhouse-Geisser is significant .040
and Huynh-Feldt is
significant .027 for the MOVES*IAC interaction.

The Tests of Within Subjects Contrasts indicates a significant cubic effect
(.039) for MOVES*IAC.

So yes.

Paul


==================
Paul McGeoghan,
Application support specialist (Statistics and Databases),
University Infrastructure Group (UIG),
Information Services,
Cardiff University.
Tel. 02920 (875035).

>>> "Statisticsdoc" <[hidden email]> 05/02/2007 13:17:56 >>>
Paul,

Do you have a significant interaction between MOVES and IAC (i.e., is there
evidence that the slope of the within-subject factor varies as a function of
the between-subject factor)?

Best,

Stephen Brand

For personalized and professional consultation in statistics and research
design, visit
www.statisticsdoc.com


-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]]On Behalf Of
Paul Mcgeoghan
Sent: Monday, February 05, 2007 6:02 AM
To: [hidden email]
Subject: repeated measures custom contrasts for linear trends


Hi,

I have a customer with a within-subject factor (MOVES) with 10 levels and a
between subject factor
with 3 levels (IAC).

He wants to test if there is a linear trend at each of the 3 between subject
factor levels.

What would be the syntax for this?

I currently have the syntax below:

GLM
  moves1 moves2 moves3 moves4 moves5 moves6 moves7 moves8 moves9 moves10 BY
iac
  /WSFACTOR = trial 10 Polynomial
  /METHOD = SSTYPE(3)
  /EMMEANS = TABLES(iac) COMPARE ADJ(BONFERRONI)
  /EMMEANS = TABLES(trial) COMPARE ADJ(BONFERRONI)
 /EMMEANS = TABLES(iac*trial) COMPARE(iac) ADJ(bonferroni)
 /EMMEANS = TABLES(iac*trial) COMPARE(trial) ADJ(bonferroni)
  /PRINT = DESCRIPTIVE
  /CRITERIA = ALPHA(.05)
  /WSDESIGN = trial
  /DESIGN = iac .

Thanks,
Paul


==================
Paul McGeoghan,
Application support specialist (Statistics and Databases),
University Infrastructure Group (UIG),
Information Services,
Cardiff University.
Tel. 02920 (875035).