Questions tagged [wilcoxon-signed-rank]
a non-parametric rank test to compare two paired samples, whether values in one are bigger than in the other. This test is NOT the same as the sign test.
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Comparing standardised values of microbial colony perimeters
I’m having a statistical problem (a rather major one) and I was wondering if you could help. I’m researching microbial chemotaxis and analysing colony perimeters by scanning their fluorescence. ...
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I'm having trouble choosing between Wilcoxon matched pairs test and McNemar test for a data set
I have a data set on a large group of long-term stroke survivors. I need to determine whether there is a difference in ability (on a scale of 1-10) between their left and right arms. The ordinal data ...
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Wilcoxon signed-rank test - the "distribution of differences is symmetric" assumption
How do you define "symmetric" here? In a paired test scenario, if one treatment consistently produces better outcome than the other treatment, I'd imagine the differences to be clustered on ...
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Post-hoc tests after Friedman test
In Statistical Comparisons of Classifiers over Multiple Data Sets (p. 12) Janez Demsar suggests to use the Bonferroni-Dunn test as a post-hoc test after the null hypothesis of an initial Friedman test ...
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Why is p value different in same hypothesis? [closed]
wilcox.test(weight ~ group, data = my_data, paired = TRUE)
wilcox.test(weight , group, data = my_data, paired = TRUE)
can anyone specify the difference to me ...
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Friedman test_multiplicity
I'm performing Friedman test to see if there is a difference between 8 treatments, then if it is significant I'll do Wilcoxon signed rank test to see which pair is significant. I wonder if I should ...
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One sample Wilcoxon Rank-Sum Test to compare percentiles
I have 10th, 25th, 50th, 75th and 90th percentiles of a population which is NOT normally distributed. On the other hand, I have a sample from that population and I want to test if its percentiles are ...
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Creating a reference group to have equal sample sizes for Wilcoxon signed rank test
I am analyzing three years' worth of data. For some descriptive analysis, I want to know if there is a difference in the median between, $year_1$ and $year_2$ compared to $year_3$. To do this, I ...
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Can you accept the alternative hypothesis is the Wilcoxon rank sign test says to retain the null hypothesis?
All the tests that were carried out prior to WRS test shows to reject null hypothesis, but WRS test is saying to retain the null hypothesis.
However, rejecting the null hypothesis makes more sence. Is ...
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Calculating effect size of wilcoxon test after correction for multiple comparisons using R
I am trying to compare two amino acid concentrations after two treatment variations. The data is not normal distributed, so I have to use non-parametric tests. I calculated the adjusted p values, but ...
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Independence assumption of non-parametric tests (Mann-Whitney & Wilcoxon Signed rank)
I'm interested in testing (one at a time) these two hypotheses using the...
Mann-Whitney U test.
H0: The probability that an observation in Group1 is greater than an observation in Group2 is 0.50
But ...
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Wilcoxon Signed-Rank Test N>300
There were similar questions here but as a person with little knowledge about statistics I couldn't understand any of it. I was looking for critical value tables that reached up to to higher amounts ...
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A nonparametric test for multivariate paired data? (i.e. multivariate version of wilcoxon signed-rank test?)
I have a set of datasets that have undergone 6 different pre-processing approaches prior to undergoing dimensionality reduction with two different algorithms, after which I score them for structure ...
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Exactly what does the Wilcoxon signed rank test compare?
The Wilcoxon signed rank test is a nonparametric version of the t-test. That is, it converts parametric values, which may be non-normally distributed into EDIT for Glen_B more normally distributed ...
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