# 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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### Appropriate tests on discrete and paired data

I am going back and forth on which tests to do. I have two paired variables, that are both positive integers (0,1,2,3...etc). $n = 559$. The variables represent the error resulting from two different ...
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### Minimum sample for non parametric test?

Exactly how many sample to be minimum size for non parametric test? Right now i have 3 data with really2 small sample size 1. 5 pairs for wilcoxon signed rank test (pretest and postest in 1 place) 2. ...
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### Why is the upper bound of the 95% CI infinity when using a one sample wilcoxon?

I've been calculating 95% confidence intervals around the psuedomedian in a one sample wilcoxon signed rank tests, with a "greater" alternative and the mu = 0. That is, I have been exploring ...
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### Relationship between p-values and effect size

I did a Wilcoxon signed rank test to understand whether there is a difference in average sales in 9 different counties. There are multiple pairs of counties that are significantly different. Would it ...
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### Statistical method comparing difference in extreme percentile

Statistical methods like wilcox.test to t.test test differences in medians or means. I would like to compare the difference in ...
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### Combining paired and unpaired samples in Wilcoxon/MWU test

I am trying to compare numbers in two sets (X and Y) to test if numbers in one of the set are statistically larger than the others. However, some of the numbers are paired, and some are not. For ...
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### Wilcoxon Rank-Sum vs Signed Rank for paired

I'm working with a dataset that contains paired samples (but some samples are missing their pair) and I want to check for an association between a binary variable and a bunch of numeric variables. ...
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### (Repeated) Cross-Validation and Wilcoxon test

Is it a common practice to apply the Wilcoxon test to the (repeated) cross-validation score estimates when comparing two different models? I've read that most of the time the average of the cross-...
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### Is the Wilcoxon Rank-sum test the best option with many near 0 values >0?

I have a two very large datasets. They look something like this, but with a few thousand rows. They are the total number of tyrosines in a short DNA sequence with a length of up to 5. A would precede ...
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### Why should we report Z when reporting the results of a Wilcoxon Signed Rank test?

I read these guidelines on how to report statistics in APA style and it recommends to report the Z score when reporting the results of a Wilcoxon Signed Rank test. Why is it important to report the Z ...
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### Can I use wilcoxon signed rank test for time series data

I have a question about wilcoxon signed rank test. I have 2 different speed profiles (speed starts from time 0 to 100 sec) of the same participant that was given 2 different treatment. I would like to ...
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### Is the Wilcoxon paired rank test appropriate for this data?

I have two vectors of normalized data values representing two paired conditions ("methylation" and "expression"). A scatterplot of my data looks like this: I'd like to know if I am using the Wilcoxon ...
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### Zero differences and Wilcoxon signed rank test

I am wondering if the Wilcoxon signed rank test is an appropriate test for my data, that does not follow a normal distribution. I have 150 datasheets of numbers of drugs measured at two points in time....
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### Wilcoxon Rank Test Pre/Post By gender

I am trying to compare the paired pre to post-responses in a student survey to see if gender plays a role. I was told to do a wilcoxon signed ranked test, and I can get the mean and p-value by each ...
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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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### 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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### Wilcoxon Matched-Pairs Signed-Ranks Test result interpretation

Lets assume that I am comparing pre intervention weight and post intervention weight of the participant (paired data). From Wilcoxon Matched-Pairs Signed-Ranks Test I and got p-value 0.03. Am I ...
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### Understanding a proof of the relation between Walsh averages and Wilcoxon signed rank test statistic

I am trying to understand a particular proof of the relation between Walsh averages and the Wilcoxon signed rank test statistic, as given in the book Statistical Inference Based on Ranks by T.P. ...
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### How to combine effect size of Wilcoxon signed rank test

I am doing a Wilcoxon signed rank test on paired samples and it only reports effect size r and p-value. Since I am doing a meta-analysis and have calculated many effect sizes, I want to combine the ...
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### One-sample versions of the signed rank and rank sum tests?

I wonder if there are applications of the signed rank and rank sum tests in a one-sample context? Signed rank Is there a form of the signed rank test where the difference $A-B$ for each subject is ...
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### How do two of my Wilcoxon signed rank tests have the same p-values?

I'm running a statistical analysis where I'm comparing land surface temperature in matched equal sized areas (project areas and control areas) of different cities. In each city, I do it for two ...
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### Is Wilcoxon Test appropriate for paired categorical data?

There is currently a story in the news in the UK about negative effects of puberty blockers in children: 'It showed that after a year on puberty blockers, there was a significant increase found in ...
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### How to run Friedman test correctly across three sets of questionnaire data divided into sub-groups?

I am trying to evaluate the usability of three prototypes of an application and want to see if there is a significant difference in terms of usability. For this I have collected responses from users ...
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### multi-level Wilcoxon analysis

The question was originated from the paper [1] Table 3 [2], for every species, there was a data frame with two column: disease categories and the conservation index. Conservation index is numeric. The ...
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### How to consider "pratt" zero method in Wilcoxon Test of R, which is available in Python Scipy?

I have a dataset of two columns which represent rank data. These ranks are ranged from 1, 2, and 3. To test the difference in medians between these two columns, I am considering the Wilcoxon rank-sum ...
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### How to deal with ties in Wilcoxon Signed-Rank Test

I'm using a Wilcoxon signed-rank test to compare two related samples of non-normally-distributed data. The data contains some ties, so when I run the test in R, I get this warning: ...
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### Assessing significant differnces between groups of data that are spatially correlated

I'm working with data from a lattice, that is squares located in a two-dimensional structure. I want to test whether groups of squares (which then are spatially correlated) have significant ...
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### Wilcoxon signed-rank test with AUPRC

I am a little confused about this topic. I computed mean AUPRC values using 5-fold cross validation for my classifier. I understand that comparing the mean AUPRC values for two classifiers to ...
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### Survey on how frequently a group use a particular device: Which analysis methods?

I surveyed a group of photographers and asked them how frequently they used a particular type of lens for a specific type of photograph. I now want to find out which lens or lenses are the most ...
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### statistical analysis of double-treated sample data from poisson distribution

I have a question regarding the statistical significance in a biological experiment I conducted. There are cells (n=51), which are treated with chemical P (n=27) or untreated (¬P, n=24). I measure a ...
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### dependent T-test or Wilcoxons signed rank for small sample size?

I am doing an EEG study with a small sample size (N=13) and I have many variables that I need to compare (for example, onset of readiness potential, maximal point of RP, time or awareness, etc), so i ...
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### How to take into account measurements of out-of-bound cases in a statistical pair-wise comparison?

If I have time measurements of different methods, but there is a maximum time. What should I do with the cases where the maximum time was reached, but not the goal? Should I simply ignore them, or is ...
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### Wilcoxon Signed Rank Critical Values for n >40

I'm looking for critical values for Wilcoxon Signed Rank for larger values of N but can only find tables and lists for up to N=40. I am looking for either comprehensive sources of critical values for ...
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### paired subject design test of proportions

I am analyzing a performance data set and would like to compare across two different conditions. I have three subjects, which were tested over a number of trials. Each trial had a chance of being in ...
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### Which of these two ways is better to report comparison of paired data?

Suppose I am comparing the computational time of two algorithms A and B. They are solving randomized problem P. Let's say I solved the problem for seeds $1, 2, \dots, n$ with both A and B and got ...
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### How to report results from Friedman's test including post-hoc results

I have performed comparison of repeated measures for a group using Friedman’s test (K-related-samples test) and additional post-hoc analysis with Wilcoxon signed-rank test and Bonferroni correction. I ...
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### Wilcoxon-Mann-Whitney Output

I proposed a question early on infection rate data in 6 different hospitals for two years (N=12). After speaking with several people I decided that a Wilcoxon-Mann-Whitney (Mann-Whitney U, Wilcoxon ...
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### investigation of a potential change of measured values: only the simple linear regression or also compare the mean of follow-up values with baseline?

For my medical dissertation I am studying a group of 36 patients. The patients received a drug repeatedly over several months. Serum levels of two cytokines were measured in the patients both before ...
1 vote
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### Is the Wilcoxon Signed Rank Test appropriate when the Brier score is the accuracy metric?

When comparing model performance, is it valid to use the Wilcoxon signed rank test for matched pairs, when the accuracy metric is the Brier score? (Here, the Brier score is used in calculating the OOB ...
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### How to analyse ordinal data for five food samples

I've conducted a questionnaire asking participants to rate biscuit samples based on factors such as taste and look. The ratings ranged from strongly like to strongly dislike. What is the best method ...
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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 ...
1 vote
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### Alternative for Wilcoxon Test?

I'm ending my Master's Thesis, and I'm trying to figure out which test to use to calculate the significance of my data. Basically, we measured the Free Kick biomechanical parameters of several ...
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### Is Wilcoxon signed-rank suitable to test mean differences between two different, ordinal, variables?

My data consists of 10 perceived risks and 10 perceived benefits, measured on a Likert agreement scale. I would like to test if the means are statistically different. It is a single sample, evaluating ...
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### paired Wilcoxon rank test but with 3 groups

What is the statistical test I should use if I want to run a paired sample Wilcoxon’s signed rank test but I have three groups to compare instead of two?
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### The Wilcoxon signed-rank test without symmetry caused by one outlier

I am comparing two algorithms on the same input data. Now I want to see whether the difference in output is significant. For this I need to use the Wilcoxon signed-rank test, since my data is paired ...
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### Is 90% of the use of paired signed-rank Wilcoxon test incorrect due to violated distributional assumption of symmetry, or is it more general?

Everywhere, including forums - also this one, handbooks of statistical tests discussions, I can read that the paired Wilcoxon test does require the assumption of symmetry. This would mean, that: Most ...
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### Is the wilcoxon signed-rank test suitable for zero-inflated data?

I have data that look like this: (There's 285 entries) These are paired data, in that each line represents a single seal group that has been counted for entanglements using two different methods of ...
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### Wilcoxon signed-rank test for count-proportions?

Let's say that I have several agents able to take action A or B, and I am interested in showing that taking action A is more likely. So I have a table that looks something like A B 10 2 14 6 ... .....
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### Compare gain scores of two groups of unequal size and not normal distribution

I am trying to determine the effectiveness of a learning intervention that we developed. We had two groups, a control and experimental group, where we applied the intervention to the experimental ...
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