Questions tagged [wilcoxon-signed-rank]

Wilcoxon signed-rank test is a non-parametric rank test to compare two paired samples, whether values in one are bigger than in the other. Can also be used to compare one sample to a fixed value. [The test NOT to be confused with the `sign-test`].

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15 views

Testing mean in dependent non-normal samples

I have time-series data on the multi-level order book for one stock. I want to test whether the mean of the middle spread (bid-ask spread) is different from the mean of the spreads between the ...
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Proper statistical significance tests for small samples of unknown distribution

The title basically says it all; what is considered to be a proper statistical test in the literature for comparing small samples of unknown distribution? That is to say, I run an experiment something ...
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wilcox.test between multiple grouping variables in r [closed]

I have a data set with one numerical variable and 78 binary variables. I know how to perform multiple wilcox.tests between multiple numerical variables against one ...
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Descriptive statistics: T-test & Wilcoxon test [closed]

I am a beginner in R and I would like to compute descriptive statistics (mean & variance) for a variable of my dataset by groups (defined by another variable) for two different periods. Following ...
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Ways to state relationships like “A explains x% the variation in B” but when variation is not present like for non-parametric tests

Example: Income explains 70% of the variance in expenditure. Variation in driving speed can be explained by drivers' age. How does one make such statements if the test used is a non-parametric one? I ...
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What's the appropriate test to be used in this study?

I was asked by an acquaintance of mine for support in interpreting a medical study. I don't work in healthcare, thus of course this was not professional advice. Two groups of people of size $n_1$ and ...
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60 views

R removing zeros for pseudomedian and its confidence interval in wilcox.test?

It makes sense to me that we need to remove zeros to calculate the p-value in a Wilcoxon signed rank test. What confuses me is that R seems to leave the zeros deleted when computing the pseudomedian ...
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Why p-values are different

I have a data of total number of mutations and fraction of mutations in each patient for three groups of patients I want to see if these three groups are different in terms of total number of ...
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Friedman's test with different # of answer choices

Greatly appreciate your help! I am analyzing paired data across 3 groups. Data within each group is ordinal (number of genes recommended for genetic testing, with each answer choice corresponding to ...
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Within subject, Multiple treatment: testing if each treatment further increases dependent variable?

Suppose I have data that looks something like the following for a single subject: Treatments: amount of a shot they receive, such as 5cc, 10cc, 15cc, 20cc Outcome of interest: energy level Question ...
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why wilcoxon signed rank test is better than binomial

Let $\vec{x}$ be 100 iid random varibles such that $x_i \sim \mathcal {N}(0,1)$ Let $\vec{y}$ be 100 iid random varibles such that $y_i \sim \mathcal {N}(1,1)$ For this example, the signed-rank test ...
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Early stopping in wilcoxon signed rank test?

I have decided to acquire N joint samples of variables X and Y (for example, N=200), and test whether their means are different using the signed-rank test. I will repeat this procedure many times, ...
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Perform signed rank test where there are duplicates in data?

How do you perform a rank test when there are duplicates in the data? that is, we have a dataset with numbers $1,1,1,1,3,3,3,3,4,4,4,4.$ and another dataset also with duplicates.... Is the sum of ...
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Wilcoxon signed-rank test on cross-validated values

Many neuroscience papers aim to estimate the significance of classification accuracy measures (AUC-ROC for example): can one classify such behaviors better than chance with such neuronal activities? ...
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In Wilcoxon signed ranked test, what box range represents? [duplicate]

I have used R programming language to perform Wilcoxon signed ranked test between two data: ...
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Can we use a Wilcoxon signed rank test on discrete, non-normal data in a small sample size?

I am looking to validate my decision to use a wilcoxon signed rank test to test for significance in my study. Essentially, I have a small sample size (n=10) and the data is paired. I am looking to ...
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Why do MATLAB and R give different results for Wilcoxon signed rank test?

I have tried to calculate Wilcoxon signed rank test p-values using MATLAB and R. Strangely, they give different results. Concretely, my code for MATLAB is ...
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How to conduct Holm's procedure for two-sided Wilcoxon signed rank test when conducting pairwise comparisons for multiple classifiers?

I am trying to compare the accuracies of m classifiers on multiple datasets. Following the suggestion of the JMLR'16 paper "Should We Really Use Post-Hoc Tests Based on Mean-Ranks?", I have decided to ...
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Is the r effect size that is used with Wilcoxon sing rank test also good to use with sign test

Is the r effect size that is used with Wilcoxon sing rank test (more about it here: https://www.researchgate.net/post/...
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Which test statistic to use for Wilcoxon signed rank test when n < 25

The z-statistic is based on an approximation of the normal distribution. When n samples are equal or greater than 25, it could be argued that a sample is asymptotically normal, and that a z-statistic ...
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A one-way ANOVA for multiple comparison

Cheng, H., & Liu, S. (2019). Haptic Force Guided Sound Synthesis in Multisensory Virtual Reality (VR) Simulation for Rigid-Fluid Interaction. In 2019 IEEE Conference on Virtual Reality and 3D User ...
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Comparison Statitics

I have 100 respondents from whom I have collected trip data for 3 months. I dont have control group or base condition. I want to measure if the proportion of aggressive trip (Trips with atleast one ...
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Converting Cliffs delta to Cohen's d

I need some help converting effect sizes and calculating 95% CI for these effect sizes. I have a pilot study with 17 participants who completed 4 likert scale measures (Variable 1, Variable 2, ...
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29 views

What does it mean if p-values differ

I have a data for 322 items that are purchased between 2014 and 2018 by men and women. If I ran a Wilcoxon Signed-Rank test with a Benjamini-Hochberg correction on the items purchased by men and ...
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Understanding statistical test to use: T-Test vs. Wilcoxon Signed Rank vs. Wilcoxon Ranked Sum — for Visual Analog Scales in paired sample

If I were to give out a survey with questions based on a visual-analog scale, and I want to compare the results for each of these, which statistical test is generally the most appropriate? If for ...
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Is Wilcoxon test not useful in my scenario? Should I go for Friedman instead?

The background: After I've conducted a survey about preferences of users in ridesharing, I now want to construct an order of importance of these preferences (this is to answer one of my research ...
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Friedman, Repeated measures Anova, Wilcoxon-signed rank?

I am unsure which statistic test is adequate for my experimental setup: I have imaged one phantom on a CT scanner. using 2 different image scan protocols (two modes) reconstructed 3 different ...
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How to calculate a 𝑝-value for the difference between two non normal distributions of counts?

I have two NON normal distributions (a and b), they are also different lengths ...
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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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Direction of a one sample Wilcoxon signed rank test

I am comparing a selection of values which come from a non-normal distribution to 0. I've done a wilcoxon in python: result = scipy.stats.wilcoxon(values) my W ...
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71 views

Hypothesis testing with regression models

I have two regression models: a linear model with one variable, and a neural network with many. I want to test whether the neural network is better than the linear model. I am wondering the best way ...
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59 views

How to merge multiple one-sample Wilcoxon-tests into single test/model

I have data on the monthly rent of a certain group of people (n = 10 people). We call them people X. These people live in different neighborhoods (very far apart). Furthermore, I have data on the ...
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Wilcoxon signed rank with multiple repetition

How could I do Wilcoxon signed-rank statistical significance test with multiple replications in python or other languages? (since python does not have any parameter as the input of the function for ...
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Analyzing ABn test when normality is not met

I'm analyzing an unpaired A/B/C/D test to assess whether the mean or median of population B/C/D is higher than the one of A. As shown from the left plot the normality distribution cannot be assumed. ...
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paired test VS unpaired test

I have a set of paired measurements which were collected before and after some trigger for a set of users. Users can react differently to trigger, i.e for some measurements before trigger are larger ...
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Treatment of Ties in sign test (paired-samples sign test)

I'm curious about the validity of removing/ignoring ties when calculating the p-value for the sign test. By ties I mean ($x_{before} = x_{after}$, where $x$ represents the measurement). According ...
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What Wilcoxon Test is 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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Why several studies change logical paired/unpaired assumption from omnibus to post-hoc?

There are several studies of highly-referenced researchers where a paired post-hoc test (e.g. Wilcoxon signed-rank) follows the omnibus unpaired test (e.g. Kruskal-Wallis): From Huang et. al "THE ...
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1answer
58 views

Test for multiple samples of ordinal data

I have 10 independent samples of ordinal data ranked 1-3. I also have predicted ranks for the same data set. I want to test if the predicted ranking matches the observed ranking at a rate better ...
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119 views

Kolmogorov-Smirnov test vs. Wilcoxon signed-rank test for two samples

I would like to ask a question about the usage of Kolmogorov-Smirnov test and Wilcoxon signed-rank test to show that two samples have the same distribution (specifically, log-normal). Specifically, I ...
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548 views

Wilcoxon signed rank test – critical value for n>50

I have seen that someone has asked a similar question a few years ago, but unfortunately the answer is not helpful. I am in the process of estimating a Wilcoxon signed rank test with a n=63 by hand. ...
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Compare change of ordinal variables between admission and dismission with different levels

I would like to compare difference between admission and dismission fron rehab center of an ordinal variable relative to diagnosis. At admission patients are divided in 3 groups (Emersion, SMC or SV, ...
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21 views

Wilcoxon signed rank test?

I would appreciate any advice possible. I am doing a study to look at change in value of my markers before and after a device change. My data is non-normal. I need to see how the value changes from ...
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1answer
63 views

In R (nlme/lme4), how do I compare two linear models with different sample sizes and different groups? [duplicate]

First off, I have a dataset with sparse longitudinal data. There are 30 individuals with 1 sample, 30 individuals with 2 samples, and 5 individuals with 3 samples. Various categorical variables are ...
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47 views

Statistical test for rubric-scored student responses

I am generally a qualitative researcher, but in my current study I am asking a research question that requires (very little, but some) quantitative tools. Simplistically, I have scored students' ...
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mutation difference

I am hematology/oncology physician. i am doing project in CNS lymphoma. i have a question about the best method to calculate if there is any statistical difference in mutation frequencies between 2 ...
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Potential problem in using paired t-test or Wilcoxon if the two samples consist of multiple draws from same group?

I have an experiment that works loosely works as follows: There are ten subjects in each treatment. There are two treatments, A and B. Each treatment has 8 rounds. In each round, each subject is ...
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64 views

Comparing the performance of two algorithms with Wilcoxon Signed-Rank Test

I have two algorithms A and B which have to compute a solution to some problem. Each solution is given some objective value ...
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62 views

Wilcoxon signed rank test - interpretation

I have 6 dependent variables that were measured on a 5 point Likert scale (treated as interval here). I want to test if their means differ significantly from the midpoint 3. As the normality ...
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Is my interpretation for Wilcoxon Signed Rank test correct?

I ran a wilcoxon signed rank test on paired samples where the outcome variable was a test score. The samples were paired by as siblings (younger and older sibling). I have a problem interpreting the ...

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