Questions tagged [dunn-test]
Dunn's test is a non-parametric pairwise multiple comparisons procedure based on rank sums, often used as a *post hoc* procedure following rejection of a Kruskal–Wallis test. As such, it is a non-parametric analog to multiple pairwise *t* tests following rejection of an ANOVA null hypothesis.
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Appropriate way to correct for multiple comparisons in this case
I am trying to compare the performance of an optimisation algorithm on different objective functions. The functions can vary in their form (4 different types) and dimension. I would like to first ...
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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 ...
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Strange results using Dunn's test [closed]
I am receiving a result that seems very counter-intuitive using the Dunn's test. My data is illustrated in the plot below. I have 5 groups (labelled muscle1a, muscle1b, muscle2, muscle3 and muscle4).
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When to use an adjustment method for Kruskal-Wallis + Dunn's and which method?
I need to do multiple pairwise comparisons among 5 groups (Treatment 1, Treatment 2, Treatment 3, Positive Control, Negative Control) for different tests and times. Each group has $10$ individuals, ...
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Bonferroni-Dunn Critical differences
I was reading about visualizing post-hoc tests and I happened to come across a Python package called Orange.
Looking into the package, the function used for calculating the CD value seems to be ...
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Having trouble with my analysis. I have no one to ask. I thought I would post here
I performed an experiment where I shocked fish eggs at different times prior to first cellular cleavage, this was to create tetraploid fish larvae.
I have a control group and then 9 treatments (60, 65,...
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Dunn pairwise test becomes insignificant between two groups if I add datapoints to the third group
I am doing pairwise comparisons between 5 groups. The Dunn test with Bonferroni adjustment only came out significant for two groups (say A and B). However, when I added 5 data points to one of the ...
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The lack of evidence to reject the H0 is OK in the case of my research - how to 'defend' this in the discussion of a scientific paper?
It is probably best if I give an example because I would like to be well-understood, and I do not know how to deal with the following situation:
I analysed, using the Kruskal-Wallis test (post hoc ...
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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
...
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Test on significant difference
I need to test if there is a significant difference in leakage between prototypes. I've tried kruskal wallis and post hoc wilcoxon pairwise and Dunn-Bonferroni test, and the post hoc test always say ...
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Questions about Dunn's test
Authors in a paper state that they use the 'Bonferroni-Dunn test' as a post-hoc test. Is the 'Bonferroni-Dunn test' just a Dunn's test with Bonferroni adjustment or is it a different test (after ...
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Why do the results of Dunn's test in GraphPad Prism and R differ?
I have three sets of data, to which I want to apply Dunn's test. However, the test shows different results when performed in GraphPad Prism and R. I've been reading a little bit about the test here, ...
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Run Kruskal-Wallis (and Dunn's Test) with multiple responses in R
I want to compare three groups with each other and have chosen the Kruskal-Wallis test and then the Dunn's test as post-hoc test.
If I have a data set like this:
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Dunn's post-hoc Test after Kruskal, 'which one is more effective?' after significant difference
Dunn's test yielded the result that there is a significant difference in revenue between group 1 and group 2 after Kruskal.
In classic one way ANOVA case, if the result is same as above, you see ...
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Is it appropriate to remove biologically meaningless pairwise comparisons after Dunn test for a post-hoc(FDR) analysis for multiple comparisons? [duplicate]
I have four individual groups(A, B, C, & D)
Differences between the groups are being analyzed by the Kruskal-Wallis test followed by Dunn's test for multiple comparisons (dunnTest command in R). ...
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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 ...
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Is the Conover-Iman post-hoc test is better to use than Dunn's with small samples size after the KW test since it use the t-test on the ranks?
I know that we use the t-distribution to be able to know if two small-size samples with a normal distribution (n < 30) are different or not (Student's t-test). If we have a bigger sample with a ...
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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 ...
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Adjusted significance level in SPSS for Kruskal Wallis Post Hoc Test - Bonferroni adjustment
I am making a pairwise comparison using Dunn's post hoc test with Bonferroni correction. However, I am a bit confused on the interpretation of the adjusted significance on SPSS. I am making 10 ...
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How to report? Significant difference for Kruskal-Wallis test, but not for ad hoc pairwise comparison with Bonferroni
I performed Krusal-Wallis test in SPSS and got a borderline significant P (0.042). then, the post hoc pairwise comparison with Bonferroni-Dunn correction showed no pairwise significant difference. I ...
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Should I rank my data before doing post hoc Dunn test?
I am trying to compare multiple algorithms using the Friedman test and post hoc Dunn test. I know that we should use the rank of our data before performing the Friedman test, but should we rank the ...
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Why does my omnibus test do not agree with post hoc test?
So I am running a simple Dunn's Test on my data. After running the Kruskal-Wallis H Test, it returned a result
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Bonferroni adjusted p values (from a dunns test)
Are these P values to the same alpha value; ie, if adj p > 0.05 then there is no significant difference? also what does it mean when p = 1 (because this has happened for some of mine yet none of ...
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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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Choosing the right test to compare the difference in mean between 3+groups according to the data we have (param vs non-param, sample size..) [closed]
I hope everyone who reads this is fine. I come to you for help, I am a student in data analysis, but I am not yet familiar with everything, especially regarding tests.
I have 3 groups of independent ...
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How to get the standardized z-statistic from dunn.test-package in R?
Sorry if this is a trivial question, but I couldn't find anything on it.
I am running a Dunn-test with the dunn.test-package:
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Is Dunn-Sidak approach in MATLAB multcompare identical to so-called Dunn's test?
I've asked the same question elsewhere.
These two articles recommend Dunn's test as non-parametric post hoc multiple comparison test following Kruskal-Wallis test.
How the Dunn method for ...
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When doing FDR correction in graphpad prism after Kruskal-Wallis does the programme automatically perform a Dunn test?
I used the Benjamini-Hochberg FDR correction in graphad after performing a Kruskal-Wallis test. This gives me a list of individual P-values.
The graphad website says that if you select the FDR ...
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Likert Analysis - Dunn's Test (Stata)
Similar to previous questions but I'm still a little confused as to whether I've followed the right process/understood the results correctly.
For a research project I'm conducting I used Likert ...
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Is Kruskall-Wallis H test suitable to influence marketing plan after survey?
I've run a survey which received around 270 responses from a population of around 5,500. The survey asks brief demographic questions followed by opinion questions, akin to the following:
Demog Q 1: ...
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Difference in adjusted pvalues for comparisons between classes when using complete data and only two classes using dunn.test::dunn.test() in R
I am studying carbon content between land cover classes in patagonia and I want to test for statistically significant differences in my data. Since my data doesn't follow a normal distribution, I ...
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Statistical Comparison of Algorithms by User Ratings
I have an experimental setting where I compare 3 algorithms on the same dataset(n_sources), through user subjective evaluation of the produced outcomes(each algorithm does a different kind of sound ...
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Dunn's test: is it appropriate to use p-values to interpret relative between group similarity
For a set of data that I collected, I used the Kruskal-Wallace test to determine whether there were between-group differences in the parameter I measured. It returned a significant result, so in order ...
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Kruskal Wallis test or Friedman for multiple preselected unmatched pairs
I am unsure whether I should use Kruskal Wallis test or Friedman's test in the following case, where I am required to use a non-parametric test while compensating for multiple comparison with a post ...
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Is dunn.test for two samples equivalent to wilcox.test?
I know that dunn.test is generally used as a post hoc after Kruskall Wallis to see which groups are different, but to generalize the function I am writing, I was wondering if when only using two ...
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What are the (practical) differences between Tukey's HSD and the Dunn-Sidak correction procedures?
I have a data set with three groups, one of which is a control and the other two groups have been administered either a moderate or a high dose of a drug. The data are not normally or log-normally ...
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Is it appropriate to remove meaningless pairwise comparisons from a post-hoc analysis before correcting for multiple comparisons?
I have four individual groups with two controls and two interventions. The second control group is specifically related to the first the intervention group, making the comparison to the second ...
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Problem with Dunn's post hoc test to compare a lot of groups?
I have a dataset were people sampled litter at 12 different locations. As the data does not have homogeneous variances I performed a Kruskal Wallis rank sum test (which came up significant) and ...
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Does Dunn Test require multiple comparisons correction?
If I compared 8 groups with a single Kruskal-Wallis test and it came back positive (<0.05), and then was interested in conducting a Dunn Test to determine which pairs differed between each other, ...
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Dunn-Bonferroni: All three differ significantly?
I have this huge knot in my head while writing my thesis atm. I am totally untalented when it comes to statistics, so it could be that my question is easy to answer for some of you.
I did a Kruskal-...
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Comparing count data from multiple groups, Kruskal-Wallis with Dunn post-hoc or GLM with Poisson distribution?
Stats novice. I am comparing counts of microplastic artefacts from multiple independent sites, my null hypothesis is that there is no difference in counts between the sites.
So far I have tried ...
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Mann Whitney U test or Kruskall-Wallis + Dunn test as a post hoc?
I performed a set of inhibition experiments where Lactobacilli supernatants where tested against a pathogen cell culture. These experiments were carried out in a 96-well plate where pathogen was ...
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How to read the result of of posthoc kruskal dunn test?
How to read the result of of posthoc kruskal dunn test? Specifically, what do the values in the table below tell me?
I have 6 treatments and I first did a Kruskal-Wallis test to confirm that the ...
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Is it possible to get a CI for the difference in median response between two groups via Dunn test?
Dunn test for two groups is equivalent to Kruskal-Wallis. The null is the absence of stochastic dominance, but if we impose some more restrictions we can assume that the null is the equality of ...
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How do I know which of my groups are significantly different? Kruskal-Wallis, Dunn's test
Answers to other posts that are almost identical to my question are still confusing to me...
my data is nonparametric, unequal sample size, unequal variance, so I've decided that kruskal-wallis is ...
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Multiple comparisons and power analysis
I would like to compare 4 different groups for 10 different variables (the biodistribution of a material in different organs). Someone suggested me to use a Kruskal-Wallis test with Dunn's post-hoc ...
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Interpreting the results of the Dunn test
I've seen some answers that come close to what I'm asking but not quite. I've run a Kruskall-Wallis test that rejected the null hypothesis. Now, I've run the Dunn test, but I'm wondering if I am ...
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How to report the results of a Dunn's multiple comparisons test
I am a bit confused about Dunn's Multiple Comparisons test. My data are non-normal, and I'm comparing the sizes of fish in different years. Here's what I'm not sure about:
1) What is compared? Dunn (...
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If two groups are significant in a Mann-Whitney U test, should they also be significant in a Dunn's test? [duplicate]
I just ran across something that I thought was interesting but don't fully understand. I have some categorical data that I am comparing in R. I use a Mann-Whitney U test when there are just two groups ...
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Dunn's test null hypothesis
According to this link:
https://stats.stackexchange.com/tags/dunn-test/info
The null hypothesis for the two group Dunn's test is that one group does not stochastically dominate the other. Is this ...
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