All Questions
Tagged with multiple-comparisons nonparametric
54
questions
0
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0
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14
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When is Tukey post hoc test result identical to Games Howell post hoc test for Welch ANOVA?
In what situations is the Tukey post hoc test identical to the Games Howell post hoc test? I have an ANOVA analysis where HOV is violated and I have a statistically significant Welch ANOVA result. I ...
- 341
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29
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Why does the Dunn's test in online calculator rejects the null hypothesis while my manual computations cannot reject it?
In my own manual calculations of the Dunn's Test in google sheet, using the formula from a YouTube video, I managed to calculate the same Test Statistic as the online calculator.
However, using the ...
1
vote
2
answers
352
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SIgnificant ANOVA but not significant post hoc ... what can I do?
I am analyzing some IHC data on the density of cells in two brain regions(factor 1) in two closely related species(factor 2). My data is composed of an n of 6 for each species and is not normally ...
3
votes
1
answer
55
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Bonferroni correction gives weird results in R
I have this dataset:
Treatment
data
T1
0
T1
0
T1
0
T10
0
T10
0
T10
0
T11
0.2
T11
0.2
T11
0.2
T12
0
T12
0
T12
0
T2
0.7
T2
0.6
T2
0.6
T3
0.8
T3
0.7
T3
0.8
T4
0.3
T4
0.3
T4
0.4
T5
...
- 53
3
votes
1
answer
210
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Kruskal-Wallis returns only one significant group (out of 4 groups), when significant group is removed and test redone, another group is significant?
I am comparing 4 groups of samples using SPSS. The groups are 4 bathymetry groups (>0m, >-1m, >-2m, >-3m). Within each group are a number of samples n. Each sample has a recorded seagrass ...
- 31
2
votes
2
answers
266
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Need for bonferroni correction
I need help understanding if I need to / how to apply a bonferroni correction!
I have one continuous variable and three unrelated groups that have completed scores on this variable (Groups: A,B,C). I ...
- 31
1
vote
1
answer
1k
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How to do pairwise comparisons for Kruskal Wallis test?
If the null hypothesis in the Kruskal Wallis test is rejected, How can we perform pairwise comparisons? Can we apply Dunnett's Test for that?
- 11
1
vote
2
answers
82
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Are t-tests good choices here?
I would like to test if two groups of participants (dark-eyed and light-eyed individuals) respond to a drug differently over time. The hypothesis is that the drug reaches its peak effects sooner but ...
- 13
1
vote
1
answer
43
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Which pair of two distributions are more similar?
Suppose I have two pairs of distributions: distributions A and B in Pair 1, distribution C and D in Pair 2. There are non-parametric tests to determine if there is evidence to say that the ...
- 125
0
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230
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On assumptions and calculation of O'Brien's "Global Statistical Test" for Multiple Endpoints Analysis
As I understand, O'Brien's Global Statistical Test (GST) (https://pubmed.ncbi.nlm.nih.gov/6534410/) for Multiple Endpoints Analysis is a method for mapping a multivariate problem on a univariate scale....
- 127
3
votes
1
answer
198
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Multiplicity correction after performing non-parametric tests
This is a theoretical question.
I am wondering if multiplicity correction is applicable in the case of non-parametric tests.
I have performed some Mann-Whitney U rank test on two independent samples ...
- 120
1
vote
1
answer
2k
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How do I interpret the p-value in a Dunn-test?
I conducted a Kruskal Wallis test for my sample sizes, and this is what I got:
Kruskal-Wallis chi-squared = 12.138, df = 4, p-value = 0.01635
The p-value is below 0.05, so I know there is a ...
- 15
4
votes
2
answers
2k
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Which pairwise comparison tests are best to use after the Kruskal-Wallis test (Dunn, Conover-Iman or Steel-Dwass-Critchlow-Fligner test)?
I have 3 sampling sites where I took 3 water samples in each site. I chose to do the Kruskal-Wallis test to find out if there is a significant difference in total nitrogen between the sites. I did not ...
2
votes
0
answers
464
views
Multiple comparisons version of Kolmogorov-Smirnov test
Suppose $\mathbf{y}_{i} $ and $ \mathbf{x}_{i}\,$ are length-$m$ vectors and $D_{i}$ is some arbitrary distribution $(i=1,...,N)$. I would like to conduct the following hypothesis test:
$ H_{0}: \...
- 388
0
votes
1
answer
107
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Calculate fraction of multiple tests for which the null hypothesis was rejected
Consider a test (e.g., a permutation test) that tests, at the individual level, if a binary event occured or not.
A paper that I was recently reading, for example, tested whether or not a pair of two ...
- 3