Dear all,
I have a repeated binary measurements and can't figure out how my data
will work.
Response (dependent, Y/N) was repeatedly recorded across Time
(categorical : 3 time points) with different Treatments (categorical :
2 levels).
The problem is that each subject was only assigned either the first or
the second time point. All were assigned into the third time point,
though. Thus, it seems to me that Subject (random) is cross-over withn
Time (fixed) effect.
For example,
Treatment Time Res
sub1 A 1 Y
sub1 B 1 N
sub1 A 3 Y
sub1 B 3 Y
sub2 A 2 Y
sub2 B 2 Y
sub2 A 3 N
sub2 B 3 N
So far, I have played around the following models and I feel that the
fist one produces feasible outcomes, even though the last one seems to
be the right syntax.
lmer(TGA ~ Treatment + Time + (1|Time) ,family=binomial)
lmer(TGA ~ Treatment + Time + (1|sub) ,family=binomial)
lmer(TGA ~ Treatment + Time + (1|sub) + (1|Time) ,family=binomial)
Can anyone suggest a solution to this? And please correct me if I'm wrong
Best,
cross-over design
2 messages · Soyeon Ahn, ONKELINX, Thierry
lmer(TGA ~ Treatment + Time + (1|sub) ,family=binomial) is the correct syntax Best regards, Thierry ---------------------------------------------------------------------------- ir. Thierry Onkelinx Instituut voor natuur- en bosonderzoek team Biometrie & Kwaliteitszorg Gaverstraat 4 9500 Geraardsbergen Belgium Research Institute for Nature and Forest team Biometrics & Quality Assurance Gaverstraat 4 9500 Geraardsbergen Belgium tel. + 32 54/436 185 Thierry.Onkelinx at inbo.be www.inbo.be To call in the statistician after the experiment is done may be no more than asking him to perform a post-mortem examination: he may be able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher The plural of anecdote is not data. ~ Roger Brinner The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data. ~ John Tukey
-----Oorspronkelijk bericht-----
Van: r-sig-mixed-models-bounces at r-project.org
[mailto:r-sig-mixed-models-bounces at r-project.org] Namens Soyeon Ahn
Verzonden: woensdag 16 februari 2011 10:11
Aan: r-sig-mixed-models at r-project.org
Onderwerp: [R-sig-ME] cross-over design
Dear all,
I have a repeated binary measurements and can't figure out
how my data will work.
Response (dependent, Y/N) was repeatedly recorded across Time
(categorical : 3 time points) with different Treatments (categorical :
2 levels).
The problem is that each subject was only assigned either the
first or the second time point. All were assigned into the
third time point, though. Thus, it seems to me that Subject
(random) is cross-over withn Time (fixed) effect.
For example,
Treatment Time Res
sub1 A 1 Y
sub1 B 1 N
sub1 A 3 Y
sub1 B 3 Y
sub2 A 2 Y
sub2 B 2 Y
sub2 A 3 N
sub2 B 3 N
So far, I have played around the following models and I feel
that the fist one produces feasible outcomes, even though the
last one seems to be the right syntax.
lmer(TGA ~ Treatment + Time + (1|Time) ,family=binomial)
lmer(TGA ~ Treatment + Time + (1|sub) ,family=binomial)
lmer(TGA ~ Treatment + Time + (1|sub) + (1|Time) ,family=binomial)
Can anyone suggest a solution to this? And please correct me
if I'm wrong
Best,
_______________________________________________ R-sig-mixed-models at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models