All Questions
15
questions
1
vote
0
answers
64
views
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
votes
0
answers
143
views
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 ...
- 49
1
vote
4
answers
131
views
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 ...
- 11
0
votes
0
answers
87
views
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 ...
0
votes
0
answers
2k
views
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,...
- 101
1
vote
0
answers
129
views
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 ...
- 11
1
vote
0
answers
248
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
...
.....
- 11
9
votes
5
answers
8k
views
Wilcoxon Signed Rank Symmetry Assumption
The assumption of symmetricity for signed rank test (and its relevance) is becoming extremely confusing for me. I am hypothesizing that sub-population A (before treatment) and sub-population B (after ...
- 93
28
votes
2
answers
19k
views
Non-parametric test if two samples are drawn from the same distribution
I would like to test the hypothesis that two samples are drawn from the same population, without making any assumptions about the distributions of the samples or the population. How should I do this?
...
- 467
12
votes
1
answer
31k
views
How to choose between sign test and Wilcoxon signed-rank test?
I am trying to pick one from these two tests to analyze paired data. Does anyone know any rules of thumb about which one to pick in general?
- 387
2
votes
2
answers
714
views
Inverted nonparametric rank test
I have two related samples, for which I want to prove they are not significantly different (normally you would test for the opposite, i.e. samples are significantly different).
If I use Wilcoxon ...
- 416
3
votes
1
answer
3k
views
Critical value for Wilcoxon one-sample signed-rank test in R
I am trying to find the critical value for the Wilcoxon one-sample signed-rank test. Currently, I can find the value using tables. I looked at qwilcox() in R, but ...
- 133
4
votes
2
answers
1k
views
Why am I getting inconsistent results from Wilcoxon signed rank test and Kruskal-Wallis test?
I am doing a study on 3 drugs, comparing response pre-post treatment. My objective is to know if these drugs are effective and which one is better. I used non parametric tests since the results weren'...
- 49
2
votes
1
answer
460
views
Wilcoxon signed-rank test. Is it necessary?
I have a sample with millions of points. Every point $x$ has two values associated, let's say $A_{x}$ and $B_{x}$. I calculated the mean values of A and B in the sample:
$\overline{m}_{A} = 0.19 \...
8
votes
4
answers
6k
views
What method is preferred, a bootstrapping test or a nonparametric rank-based test?
I want to perform a single-tail test on a single sample of real numbers (N~100) against an expected value. The population is known to be not normally distributed. So from what I've read about stats, I ...
- 255