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`].

Filter by
Sorted by
Tagged with
1
vote
0answers
14 views

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 ... .....
0
votes
0answers
10 views

Which one to use: Cliff's Delta or Vargha-Delaney's A12 to know the effect size?

I have to compare the predictions of two regression models (both are predicting on same dataset, but one is using entire data and another one is using only pruned data). To know whether there mean ...
1
vote
2answers
28 views

Does Wilcoxon Signed Rank (paired test) in R automatically analyse data by row?

I have multiple rows of observation periods [OP] (of varying durations) showing the average food intake rate of the first quarter of the OP compared to the last quarter of the OP. See the table below....
1
vote
0answers
30 views

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 ...
0
votes
0answers
24 views

Wilcoxon signed rank test for heavily tied data

I am having trouble conducting Wilcoxon test analyses on heavily tied data. I have outlined my problem as best I can below, how I have tried to address it, and the questions I have. I'd be really ...
1
vote
2answers
47 views

Interpret the results of Wilcoxon signed rank test using mean ranks?

I have two dependent samples that I want to compare using the Wilcoxon signed rank test. I've now run into a problem with a few of my variables. The difference is significant so I want to know the ...
2
votes
1answer
28 views

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 ...
0
votes
1answer
14 views

Wilcoxon signed-rank test with large dataset and non normal distribution

While the Wilcoxon signed-rank test in general doesn't assume any distribution, most exact implementations are restricted to <50 samples (i.e. scipy). Above that a normal distribution is assumed to ...
0
votes
0answers
53 views

Optimising disease model parameters using multiple comparisons of simulated versus experimantal data (geometrical means)

I run simulations for multiple dose values, Dose 1...Dose 4, and would like to find the best match between the simulated and experimental geometric means for a number of subjects, see figure. By ...
0
votes
1answer
27 views

Sample size for paired Wilcoxon test

I would like to perform a statistical test in order to compare the results of a new machine B vs the results of the current machine A. The data are in form of count values, that's why I am thinking a ...
0
votes
1answer
32 views

Wilcoxon rank sum test or wilcoxon signed rank test?

I have recorded the the rate at which water exits a tank on-site and through a video recording and it looks something like this: Water Level Flow Rate (On-site) Flow Rate (Video) 0.60 1.70 1.62 0....
0
votes
0answers
12 views
0
votes
2answers
28 views

Wilcoxon Signed Rank when positive and negative differences are equal in magnitudes

I've run into some trouble. To begin with, I have no formal education in statistics, so much of what I do is self learned and I may be blissfully unaware of some fundamentals that I've completely ...
-2
votes
1answer
22 views

What is a good P value for statistical significance when conducting a Wilcoxon Rank Sum test? [duplicate]

Is a P value of 0.4 statistically significant for a Wilcoxon Rank Sum test?
3
votes
2answers
111 views

Wilcoxon signed rank test with logarithmic variables

Im doing some basic statistics on a dataset of ours. The data is paired samples from patients in a study where we measure the ratio between component A and B in blood (AB-ratio) on people who have ...
0
votes
0answers
36 views

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 ...
0
votes
0answers
26 views

Anova vs wilcoxon

I have collected data of 73 patients with tinnitus where 45 have received a cochlear implant (therapy 1) and 28 have received a hearing aid (therapy 2). To research the impact of these two therapies ...
0
votes
0answers
26 views

Non-Parametric T-Test Alternative for Small Scale

In a small online study (N=30 participants), I asked for the participants to rate whether they prefer some stimuli A or B in a scale from -4 (prefer A) to +4 (prefer B) with 0 being a neutral "...
1
vote
2answers
28 views

Which test to use for this scenario?

A histogram of white blood cell (WBC) counts in 15 sick patients showed that the distribution was negatively skewed. If we wanted to test for differences between the published WBC count for a healthy ...
0
votes
1answer
17 views

Comparing two groups with non-negative integers?

Can I use Mann Whitney U Test (Wilcoxon Rank Sum Test) to test for differences between two populations for count data (i.e. non-negative integers)?
1
vote
1answer
35 views

Does it make sense to run Wilcoxon rank sum test with sample size of 1 or 2?

suppose I have the following numbers. ...
1
vote
1answer
56 views

Do multiple wilcoxon tests of drug sensitivity between mutated grp and wild-type grp need multiple testing correction?

I am doing wilcoxon-rank-sum tests of the sensitivity (AUC) of over 1000 drugs between mutated gene A and wild-type gene A. So, for each drug, there will be one wilcoxon test and one p-value. Since I ...
2
votes
1answer
27 views

Can someone help with the nuance in the wilcox.test function in R?

This is from a homework assignment for my grad stats class. First I generate a dataset in R: ...
1
vote
1answer
55 views

There is very slight difference but also statistically significant. Could there be a mistake?

In my study to investigate the effect of filter glasses on reading speed and contrast senstivity in albino patients, there is little change in the reading performance level n:61 patients Reading ...
0
votes
1answer
20 views

Which test fits the best here? (oncogenic signalling pathways)

I have a list of patients in rows and oncogenic signalling pathways in columns of two independent matrices One for responders to a drug one for non-responders to the same drugs If a patient gets ...
0
votes
1answer
43 views

Where do Wilcoxon signed rank critical values come from (ie how are they computed)?

Here is the table for Wilcoxon signed rank test critical values, and obviously we can decide whether or not to reject the null hypothesis for a particular scenario based on this table. I understand ...
1
vote
1answer
55 views

Comparing classifiers for multi-label classification predictions

I have a multi-label classification problem (categorical predicted values: A, B, C, D) and I want to test the null hypothesis that there is no significant difference between the classifiers, and the ...
1
vote
1answer
70 views

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 ...
2
votes
0answers
31 views

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 ...
0
votes
1answer
16 views

Metrics in comparing the rank orders of elements from 2 vectors

I am working on sampling a posterior distribution for parameters in my model using approximate Bayesian computation (ABC). I would like to come up with a summary statistic to compare the similarity/...
2
votes
0answers
46 views

How to get single sample result wilcox_test in R [closed]

I am not a regular R user so I'm struggling a bit on how to get an exact p-value and confidence limits for a single sample using the Wilcoxon Signed-Rank test. wilcox.test does not handle ties so it's ...
0
votes
0answers
18 views

One-Sample Wilcoxon Signed Rank Test when the values are identical

I'm trying to run One-Sample Wilcoxon Signed Rank Test on my data. My data contains 100 values, and I want to compare these values to a standard value. However, all the 100 values and the standard ...
0
votes
1answer
35 views

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 ...
0
votes
0answers
42 views

One Sample Wilcoxon signed-rank with a negative effect size

Hi i got a Wilcoxon signed-rank done for a one sample t-test because the data failed normality tests. Whilst the result is still significant, the effect size is -0.364. Apparantely it uses the '...
0
votes
0answers
20 views

Comparing similarity of samples under time-dependant noise (KS-test for dependant samples)

I'm measuring response times of a process under different inputs and want to check if the input correlates with the response time. The problem is that the differences I'm expecting are small while ...
0
votes
0answers
18 views

Is a Wilcoxon paired test correct for my case?

We're working with the lovely garden eels: snake-like fishes that live in big colonies, attached to the sandy sea bottom. They feed on plankton and hide in their burrows whenever something big ...
0
votes
1answer
39 views

Test statistics for hypothesis that values in one group always larger than the other group

Assume $x_1, x_2, \dots, x_n$ belong to group $A$ and $y_1, y_2, \dots, y_m$ belong to group $B$. We want to test if values in group $A$ are smaller than values in group $B$ as values in B. I design ...
1
vote
0answers
39 views

Too small sample size for Wilcoxon signed rank test, alternatives?

I have a statistical question about my research. I performed photosynthesis measurements on leaves. I have 6 increasing light intensities, and for every light intensity, I measured the photosynthetic ...
0
votes
1answer
86 views

Student's t-test versus Wilcoxon signed-rank test

Trying to understand when to use which test, am I correct when saying both these tests, test whether two samples could be taken from the same distribution, but the difference is that the student's t-...
0
votes
0answers
49 views

One-sample Wilcoxon test result does not make sense

To evaluate the correctness of a value I have given to something, I have asked a group of people to give a value for it. To evaluate the significance difference between my value with them, I am ...
3
votes
1answer
48 views

Is it appropriate to estimate the mean difference from a Wilcoxon p-value?

I am conducting a meta-analysis involving paired data (two instruments measuring the same thing). Original papers do not provide the standard deviation of the mean difference. One paper provides a p-...
2
votes
0answers
26 views

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 ...
0
votes
0answers
28 views

Can't decide between Paired t-test and Wilcoxon Signed-Rank test?

I'm using data for pre-2020 January-April and the year 2020 January-April (raw data with one datapoint per day, except for the 'pre-2020' category which is the values for one day in 2017, 2018, and ...
0
votes
1answer
50 views

What does it mean if Nemenyi test does not return that the performance of two methods are significantly different while the Wilcoxon test does?

I want to compare the performance of $N$ methods on $m$ datasets. I performed the Friedman test and after that the Nemenyi test. The Nemenyi test is though not powerful enough to conclude that there ...
0
votes
0answers
38 views

nonparametric tests for random forest regression

Ive built a random forest model which predicts temperature, humidity and energy based on 5 inputs. I obtain an R2 value of 0.92, CV(RMSE) of 14, and errors of 3.51%, 4.22%, 7.23% for each variable ...
1
vote
1answer
17 views

Can I use `wilcox_test()` to compar multiple means without `friedman_test()`?

In this example,use friedman_test() first to find significant difference between group,and then use ...
0
votes
0answers
44 views

Friedman test: non-significant post hoc (exact and Nemenyi test) should I run Wilcoxon signed rank tests or Sign tests? Or just accept the results…?

In my data, participants were tested on the same ordinal variable 3 times. In order to test for within-group differences, I ran a Friedman test. After reading this post, I ran the friedmanTest ...
1
vote
0answers
18 views

Wilcoxon Signed-Rank with unequal samples

My apologies if this is a novice question: I am using a 2 tailed Wilcoxon Signed-Rank test to determine if suspension days decrease following a year of PBIS implementation in a middle school. Sample: ...
2
votes
2answers
65 views

Is a statistically significant difference within analytical uncertainty still valid?

The isotopic analyses of two tissues across 50 specimens showed a mean difference of 0.12 ‰. A Wilcoxon signed-rank test for paired samples indicated this to be statistically significant (Z: -2.515, P ...
0
votes
0answers
24 views

Wilcoxon 2-sided test: rejection direction?

I am performing a Wilcoxon signed-rank test on some data, and I would like to show that my experiment A gives better scores than experiment B. I chose a two-sided test as I don't know if A > B or B > ...

1
2 3 4 5
8