Displaying 20 results from an estimated 900 matches similar to: "ANOVA non-sphericity test and corrections (eg, Greenhouse-Geisser)"
2008 Dec 04
1
How to get Greenhouse-Geisser epsilons from anova?
Dear all,
I apologize for my basic question.
I try to calculate an anova for repeated measurements with 3 factors
(A,B,C) having 2, 2, and 7 levels.
or with an additional fourth between subjects factor D.
Everything works fine using
aov(val ~ A*B*C + Error(subject/ (A*B*C) ) ) or
aov(val ~ (D*A*B*C) + Error(subject/(A*B*C)) + D )
val, A, B, C, D and subject are columns in a data.frame.
How
2009 Mar 03
1
repeated measures anova, sphericity, epsilon, etc
I have 3 questions (below).
Background: I am teaching an introductory statistics course in which we are
covering (among other things) repeated measures anova. This time around
teaching it, we are using R for all of our computations. We are starting by
covering the univariate approach to repeated measures anova.
Doing a basic repeated measures anova (univariate approach) using aov()
seems
2003 Jan 27
1
Greenhouse-Geisser correction
Hi all,
I was wondering whether there are any packages that provide for the
Greenhouse-Geisser correction, an adjustment used in univariate repeated
measures when the sphericity assumption is violated (both numerator and
denominator degrees of freedom are multiplied by GG-epsilon, and the
significance of the F ratio is evaluated with the new degrees of freedom)? I
have seen a few emails with
2005 Nov 23
0
Greenhouse-Geisser epsilon for interaction term
Hi,
I'm running a repeated measure ANOVA to test the effects of the
within-subjects
factors "congr", "isi" and their interaction, on the variable "latencies"
aov(latencies ~ congr*isi + Error(subj/(congr*isi)),data=dats)
"congr" has 4 levels, while "isi" has "3" levels.
I would like to check for possible violations of the
2001 Dec 14
0
Greenhouse-Geisser epsilon correction
Hi,
I've looked in the mailing list archives and found some questions
related to Greenhouse-Geisser epsilon correction. Are there any packages
providing that?
Thanks, Sven
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Send "info", "help", or
2012 Mar 21
2
Type II and III sum of squares (R and SPSS)
To whom it may concern
I made some analysis with R using the command Anova. However, I found
some problmes with the output obtained by selecting type II o type III
sum of squares.
Briefly, I have to do a 2x3 mixed model anova, wherein the first factor
is a between factor and the second factor is a within factor. I use the
command Anova in the list below, because I want to obtain also the sum
2005 Feb 22
3
Reproducing SAS GLM in R
Hi,
I'm still trying to figure out that GLM procedure in SAS.
Let's start with the simple example:
PROC GLM;
MODEL col1 col3 col5 col7 col9 col11 col13 col15 col17 col19 col21 col23
=/nouni;
repeated roi 6, ord 2/nom mean;
TITLE 'ABDERUS lat ACC 300-500';
That's the same setup that I had in my last email. I have three factors:
facSubj,facCond and facRoi. I had this pretty
2005 Feb 18
0
Suggestions for enhanced routines for "mlm" models.
Dear R-devel'ers
Below is an outline for a set of routines to improve support for
multivariate linear models and "classical" repeated measurements
analysis. Nothing has been coded yet, so everything is subject to
change as loose ideas get confronted by the harsh realities of
programming.
Comments are welcome. They might even influence the implementation...
-pd
General
2005 Feb 18
1
Two-factorial Huynh-Feldt-Test
Hi,
I'm currently working on porting some SAS scripts to R, and hence need
to do the same calculation (and get the same results) as SAS in order to
make the transition easier for users of the script.
In the script, I'm dealing with a two-factorial repeated-measures anova.
I'll try to give you a short overview of the setup:
- two between-cell factors: facBetweenROI (numbering
2005 Jun 15
1
Anohter anova.mlm problem
Hi,
yet another anova.mlm problem - it doesn't seem to end.
This time, I have a setup with a few within-subject factors and a
between-subject factor (SGROUP). Consider the most simple case with only one
within-factor (apo):
> mlmfit0 <- lm(data.n ~ 0 + SGROUP)
> mlmfit1 <- lm(data.n ~ 1 + SGROUP)
> anova(mlmfit1,mlmfit0,test="Spherical",M=~hemi,X=~1)
Analysis of
2012 Mar 05
2
new to repeated measures anova in R
Data set up as one observation/subject looks like (with a total of 10 subjects)
Two treatments: shoe type with 3 categories and region with 8 categories ==> 24 "treatment" columns
Subject PHallux PMidToes PLatToe PMTH1 PMidMTH PLatMTH PMidfoot PRearfoot LHallux LMidToes LLatToe LMTH1 LMidMTH LLatMTH LMidfoot LRearfoot DHallux DMidToes DLatToe DMTH1 DMidMTH DLatMTH
2005 Feb 23
1
H-F corr.: covariance matrix for interaction effect
Hi,
I'm still not quite there with my H-F (G-G) correction code. I have it
working for the main effects, but I just can't figure out how to do it
for the effect interactions. The thing I really don't know (and can't
find anything about) is how to calculate the covariance matrix for the
interaction between the two (or even n) main factors.
I've looked through some books
2005 Feb 23
1
H-F corr.: covariance matrix for interaction effect
Hi,
I'm still not quite there with my H-F (G-G) correction code. I have it
working for the main effects, but I just can't figure out how to do it
for the effect interactions. The thing I really don't know (and can't
find anything about) is how to calculate the covariance matrix for the
interaction between the two (or even n) main factors.
I've looked through some books
2007 Oct 16
1
library(car): Anova and repeated measures without between subjects factors
Hi,
sorry if this is explained somewhere but I didn't find anything.
How can I use "Anova" from the car package to test a modell without
between subject's factors? Suppose I have the following data
mat.1 mat.2 mat.3 di ex
1 85 85 88 1 1
2 90 92 93 1 1
3 97 97 94 1 1
4 80 82 83 1 1
5 91 92 91 1 1
6 83 83
2005 Nov 15
1
Repeates Measures MANOVA for Time*Treatment Interactions
Dear R folk,
First off I want to thank those of you who responded with comments for
my R quick and dirty stats tutorial. They've been quite helpful, and
I'm in the process of revising them. When it comes to repeated
measures MANOVA, I'm in a bit of a bind, however. I'm beginning to see
that all of the documentation is written for psychologists, who have a
slightly
2010 Aug 02
0
repeated measures with a group factor
I have a between-subjects factor, A, with three levels, and a
within-subjects factor with 4 levels. There are 6 subjects at each A
level. I get the correct F tests using the aov function with the stack
form of the data frame but I want the epsilon adjustment
(Greenhouse-Geisser, Huynh-Feldt). for nonspheriicty as well. I got the
SPSS results using the standard broad data frame (a row for
2007 May 13
2
Some questions on repeated measures (M)ANOVA & mixed models with lme4
Dear R Masters,
I'm an anesthesiology resident trying to make his way through basic
statistics. Recently I have been confronted with longitudinal data in
a treatment vs. control analysis. My dataframe is in the form of:
subj | group | baseline | time | outcome (long)
or
subj | group | baseline | time1 |...| time6 | (wide)
The measured variable is a continuous one. The null hypothesis in
2000 Aug 24
0
Is there a method to calculate Huynh and Feldt adjustments for sphericity violations
Hi,
I'm getting to grips with using R to perform repeat measures
analysis of variance and was wondering is there a potted method to
obtain Huynh and Feldt or other adjustments for sphericity
violations?
Thanks
Dominic
Dr Dominic J Barraclough
Dept Neurobiology and Anatomy,
University of Rochester,
601 Elmwood Av, Box 603,
Rochester
NY 14642
tel (716) 2753627
dominic_barraclough at
2009 Jan 30
3
Q about how to use Anova.mlm
Hi,
Am newish to stats and R, so I certainly appreciate any help. Basically I
have 50 inidividuals whom I have 6 photos each of their optic nerve head. I
want to check that the orientation of the nerve head is consistent, ie the 6
replicates show minimal or preferably no rotation differences. I'll draw an
arbitrary line between some blood vessels (same reference in each set of
replicates) and
2007 Mar 26
0
Sphericity and post-hoc analysis in a repeated-measure ANOVA
Does anyone have any suggestions for how to test for violation of the
sphericity assumption and apply the Huynh-Feldt correction to a
repeated-measure model? My model follows the format below:
Rep.anova=aov(Y~X1*X2+Error(Subject/(X1*X2),data=DataFile))
I've already looked at the explanations aov() and Error() in Baron's
“Notes on the use of R for psychology experiments and