Questions tagged [dunnett]
Dunnett's test is a multiple comparison procedure for comparing a sngle control group with many comparison groups.
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Dunnett's test for comparisons with Control - how to conduct ANOVA for 2 factors, as well as adjusting for different experimental designs?
From what I understand, before we conduct Dunnett's test for comparisons of treatments to a Control, we have to do ANOVA. However, for a 2-factor experiment, there seem to be a lot of problems to me.
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Significant results from ANOVA post-hoc Tukey's, insignificant with welch-ANOVA post-hoc Dunnett's T3
I performed one-way ANOVA tests with post-hoc Tukey's to look at multiple comparisons and got highly significant results, but noticed the $F$-value on the ANOVA was high. The SDs in the groups were ...
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balanced and unbalanced dose response experiments
Consider a dose response study where there are four active treatments (from the highest dose and lowest dose) and also a control. One goal is to test the hypothesis that treatments are more effective ...
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multicomp package and emmeans package produce different adjust pvalues for Dunnett procedure [closed]
For Dunnett adjustment, multicomp package and emmeans package in R give different results. Anyone knows why? Thanks. Please see ...
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What is the best post-hoc test to use after a two-way anova has shown there is only a significant effect when including 0 as a factor level?
I have two factors: A and B, and a response, y.
For factor A I have 3 levels: 300,400,500.
For factor B I have 3 levels: 0.5, 0.6, 0.7.
I carried out an experiment with each combination of these two ...
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Is it possible to perform a comparison to a control group with a non-parametric post-hoc test in R?
Is it possible to perform a comparison to a control group with a non-parametric post-hoc test in R? I am familiar with various post-hoc tests such as Dunn and Conover, but I'm not sure how to ...
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Equivalent to Dunnett's test for binomial endpoint?
I have a trial comparing 2 treatments vs a control group. Typically one would use Dunnett's test for this situation, but the outcome measure is binomial. It seems strange to me but I've looked for ...
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Does it make any difference to analyse change from baseline (observational study) or post-hoc contrast post vs. baseline?
I have an observational, non-randomized longitudinal study with 3 time point + baseline (t0 ... t3). Analysing solely the post-values in such trials is meaningless. I want to analyze the change from ...
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Dunn test and specific comparisons
What I need is a non-parametric alternative for Dunnett test to compare several groups with a control group (not all pairwise comparisons). And I realise that a specialised test is more appropriate ...
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Is the "mvt" (using the multivariate t distribution) accepted way of adjusting for multiple comparisons when reporting to journals?
I use the awesome package multcomp and emmeans in R. These are the places I heard about the "mvt" method for the first time. And, however, it is what it's actually done in the Dunnett or ...
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Is there any measure of Effect Size for differences assessed with Dunnett method?
I know I could use the effect size pairwise, but I have a longitudinal data, where subjects were measures multiple times and there exists ICC > 0.5. I guess the pooled SD may be altered by this ...
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Should I choose single model A+B+A:B or two models A at 2 levels of B?
I have a longitudinal model: response ~ device * time.
The device should lower the response over time.
There are two devices: A and B.
There is an interaction between the device and time.
The problem ...
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Do I have to correct for multiplicity twice if I re-run a comparison with one more hypothesis during incremental testing?
Let's say I have a set of hypotheses ordered in time. These are about comparison to some baseline moment: $H_{t1 vs. baseline}$, $H_{t2 vs. baseline}$, $H_{t3 vs. baseline}$, ...
I have 10 time ...
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How is the classic Dunnett test, with strict assumptions, related to Dunnett comparisons run on a top of very liberal models, like GLM or GEE?
As far as I understand, the classic Dunnett test is based on the t-test, applied multiple times to all comparisons vs. control and then corrected. So the assumptions of the Dunnett test must agree ...
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How is the classic Dunnett test, with strict assumptions, related to Dunnett comparisons run on a top of very liberal models, like GLM or GEE?
As far as I understand, the classic Dunnett test is based on the t-test, applied multiple times to all comparisons vs. control and then corrected. So the assumptions of the Dunnett test must agree ...
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