lme4: Parameter contrasts?

Thanks! I was also hoping there might be an easy way to bootstrap it.

Tom Carpenter, Ph.D.
Instructor of Psychology
Seattle Pacific University
3307 3rd Ave W. Suite 107,
Seattle, WA, 98119
tcarpenter at spu.edu<mailto:tcarpenter at spu.edu>
Office: (206) 281-2916
Mobile: (206) 276-1541
Fax: (206) 281-2695

On Feb 5, 2015, at 5:43 AM, Steven J. Pierce <pierces1 at msu.edu<mailto:
pierces1 at msu.edu>> wrote:

You might want to check out whether the multcomp package would handle
this. Bretz et al. (2010) describes use of the package.

Bretz, F., Hothorn, T., & Westfall, P. (2010). Multiple comparisons using
R. Boca Raton, FL: Chapman & Hall/CRC.


Steven J. Pierce, Ph.D.
Associate Director
Center for Statistical Training & Consulting (CSTAT)
Michigan State University

-----Original Message-----
From: Carpenter, Tom [mailto:tcarpenter at spu.edu]
Sent: Wednesday, February 04, 2015 8:25 PM
To: r-sig-mixed-models at r-project.org<mailto:
r-sig-mixed-models at r-project.org>
Subject: [R-sig-ME] lme4: Parameter contrasts?

Hoping someone has some advice here. I recently made the switch from using
HLM to lmer. I know that in HLM, you could do a parameter contrast (e.g.,
contrast two fixed effects against each other and test the significance of
the contrast). I was curious if anyone knows how to do this in R? I have
run a model in lmer (with standardized predictors) and wish to see if one
fixed effect is significantly larger (more predictive) than other fixed
effect.

If that is not possible in lme4, does anyone have any advice for how to
bootstrap it? I?m fine letting the thing run overnight to get a 95% CI if
anyone has any suggestions.

Tom Carpenter, Ph.D.
Instructor of Psychology
Seattle Pacific University
3307 3rd Ave W. Suite 107,
Seattle, WA, 98119
tcarpenter at spu.edu<mailto:tcarpenter at spu.edu><mailto:tcarpenter at spu.edu>
Office: (206) 281-2916
Fax: (206) 281-2695












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