All Questions
Tagged with nonparametric wilcoxon-signed-rank
94
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Statistical test for unequal sample sizes of repeated measures (non-parametric)
I'm looking to understand the differences between various sources (50) that evaluate an event based on 8 ordinal scales (varying from 2 to 4 values) associated with a discrete score between 0 and 10, ...
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1
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30
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Can I use Mann-Whitney U test for within group analysis?
I am conducting a within-group study where participants rate the perceived helpfulness of ideas on a Likert scale (DV) across two different days (Day 1 and Day 2), serving as the independent variable (...
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9
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Basic question regarding before and after intervention analysis on groups of different sample size
Apologies for the basic nature of this question. I have collected data before and after an intervention and assessed response to the intervention using a survey. This was a basic survey using a 1-5 ...
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183
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What do these Wilcoxon values tell me?
I did a pre and post-test with a small number of students ($n=12$).These values came after a science intervention that took $4$ weeks. I used a Wilcoxon test for 2 related samples as there was not a ...
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217
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What exactly does the “symmetric distribution” assumption of the Wilcoxon signed-rank test refer to? [duplicate]
I have two lists (or sets) of data that I would like to statistically compare. More precisely, I would like to check if the difference between data list one and data list two is statistically ...
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74
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How to run Wilcoxon signed-rank test for pairwise comparison of two factors with three variables each?
I performed a study where I took 9 measurements from each participant for 2 factors (time/ location) and 3 variables each. These created the following combinations:
T1L1, T1L2, T1L3, T2L1, T2L2, T2L3, ...
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411
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Paired sign and Wilcoxon tests with weighting
In R, I am using the survey package (inverse probability weighting) to conduct these tests on paired data:
Weighted Wilcoxon Signed Rank test
Weighted Sign test
However, I am struggling in doing ...
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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 ...
2
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143
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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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341
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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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131
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Business use cases for Wilcoxon signed-rank test
The Wilcoxon signed-rank test is generally used for non-parametric data (i.e. not normally distributed). When the sample gets large, the data will be approximately normally distributed. Therefore ...
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134
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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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87
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Which statistical Test should I use/ Comparing 2 groups
I am new to statistics, can someone guide me regarding the test I should use to compare the foot dimensions of 9 subjects to footwear dimensions (we have 2 footwear brands).
So, to simplify, I have ...
2
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1
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33
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Compare whether one group are significantly closer to real observations than other
I have two groups consisting of non-parametric estimated data of a phenomenon. I want to compare these two groups of estimations with a third group of real observations of the same phenomena. ...
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1
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307
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Comparing Z-Scores from Different Wilcoxon Signed Rank Tests
I have paired dependent data that represent pre-intervention/post-intervention ordinal values for the participants of a study. As part of the study, I have three separate groupings of participants: A, ...
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2
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687
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Inference of nonparametric tests as linear models
I found some statements throughout the web that suggest that most common statistical tests can be performed as general(ized) linear models (cf. here). For a Wilcoxon test the author of the referenced ...
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Wilcoxon signed-rank test for just one sample: R vs. Python
I have tried to solve a simple college exercise about WSR test: first by hand, then in Python and finally in R. But I'm having an issue with the statistic I get.
I have a small sample of 21 numbers: 4,...
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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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2
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530
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Mean difference analysis for a paired data with zero inflation. Can Wilcoxon test work?
I have a set of data that represent the sum of white matter streamlines termination in 64 regions of interest in the brain surface collected from 40 subjects.
Below is an example of a paired data of ...
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1
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95
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How to detect differences between two repeated measures for not-normally distributed variables, adjusting for a continuous covariate?
I'll explain briefly the experimental set-up.
One gruop of subject measured in two conditions:
A: with treatment (Instrumented gait analysis with foot orthosis)
B: without treatment (Barefoot ...
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182
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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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3
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1
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1k
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Calculating statistical power for non-parametric data (using Wilcoxon signed-rank tests)
I am performing a prospective-design analysis of Patient Reported Outcome Measures from a registry of patients. I have used Shapiro-Wilk test throughout to test for normality.
All data is paired and ...
2
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1
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51
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What is the drawback of using a non-parametric test when parametric alternative could have been used? [duplicate]
I want to analyze the difference between two paired samples. My initial plan was to compare them using the Wilcoxon test because I didn't want to bother checking whether the data is properly ...
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248
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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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2
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1
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57
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Non-parametric data and comparing two treatments
I would love some help with interpreting a non-parametric test. I have data on the # of seed heads produced by an invasive plant species (n=80 plants). I applied a grazing treatment in an attempt to ...
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311
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Wilcoxon signed rank test or t-test if data is highly skewed?
I have an variable that is highly skewed and I want to test whether my mean is equal to some fix value in another population. I only have the arithmetic mean of the other population. Because I prefer ...
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88
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Does it make sense to run Wilcoxon rank sum test with sample size of 1 or 2?
suppose I have the following numbers.
...
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81
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Is there any possible statistical test for this data?
I have a data set of the daily dosage of a drug that participants take against some signs and symptoms. The data are highly skewed to the left because there are a lot of patients with 0mg per day of ...
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1
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77
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Using an old trained model on a new data - comparing two populations
I have two populations with the same set of features. The range of the features' values is also the same.
I trained Random Forest Algorithm on the first population. Thus, I wonder whether or not I can ...
- 103
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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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