Displaying 20 results from an estimated 4000 matches similar to: "Correction of degrees of freedom in repeated measure aov"
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
2007 Jun 24
2
ANOVA non-sphericity test and corrections (eg, Greenhouse-Geisser)
I'm an experimental psychologist and when I run ANOVA analysis in
SPSS, I normally ask for a test of non-sphericity (Box's M-test). I
also ask for output of the corrections for non-sphericity, such as
Greenhouse-Geisser and Huhn-Feldt. These tests and correction factors
are commonly used in the journals for experimental and other
psychology reports. I have been switching from SPSS to R
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
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
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
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
2000 Oct 13
5
Random factor ANOVA, Repeated measures ANOVA, Within subjects designs.
Hi,
we are just about to evaluate R as a standard statistics package for
our institute. We looked around the help - manual, the FAQ, etc. and
did not find anything for the topics of random factors in ANOVA,
repeated measures in ANOVA, or within subjects designs in R.
Could anyone point us to any information concerning
- univariate approach to repeated measures anova
- multivariate
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
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
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
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
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
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 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
2006 Jan 11
1
F-test degree of freedoms in lme4 ?
I have a problem moving from multistratum aov analysis to lmer.
My dataset has observations of ampl at 4 levels of gapf and 2 levels of bl
on 6 subjects levels VP, with 2 replicates wg each, and is balanced.
Here is the summary of this set with aov:
>> summary(aov(ampl~gapf*bl+Error(VP/(bl*gapf)),hframe2))
>
>Error: VP
> Df Sum Sq Mean Sq F value Pr(>F)
>Residuals
2007 May 02
1
Degrees of freedom in repeated measures glmmPQL
Hello,
I've just carried out my first good-looking model using glmmPQL, and
the output makes perfect sense in terms of how it fits with our
hypothesis and the graphical representation of the data. However,
please could you clarify whether my degrees of freedom are
appropriate?
I had 106 subjects,
each of them was observed about 9 times, creating 882 data points.
The subjects were in 3
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 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
2008 Dec 17
1
repeated measures aov with weights
Dear R-help,
I'm facing a problem with defining a repeated measures anova with
weighted data.
Here's the code to reproduce the problem:
# generate some data
seed=11
rtrep <- data.frame(rt=rnorm(100),ti=rep(1:5,20),subj=gl
(20,5,100),we=runif(100))
# model with within factor for subjects/repeated measurements, no
problem
aov(rt~ti + Error(subj/ti),data=rtrep)
#model with weights
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
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