All Questions
17
questions
0
votes
1
answer
30
views
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 (...
- 1
0
votes
0
answers
9
views
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 ...
- 1
1
vote
0
answers
134
views
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 ...
2
votes
1
answer
33
views
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. ...
0
votes
1
answer
77
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 ...
- 103
2
votes
0
answers
35
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 ...
- 30.3k
1
vote
0
answers
23
views
Imposing orders on distributions based on Wilcoxon test
I am trying to figure out part of a text I am reading about non parametric tests.
In there it is stated that:
The fact that the output of a rank test is driven by the probability that a value ...
- 131
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
3
votes
1
answer
2k
views
Non-parametric equivalent of the 1-sample t-test (not paired)
I have a sample of outcomes of my algorithm and would like to test to some degree of confidence if it differs from zero.
I know I can use a 1-sample t-test (as in https://docs.scipy.org/doc/scipy/...
- 213
6
votes
1
answer
3k
views
What differentiates the wilcoxon test from t test regarding ordinal variables?
I'm wondering what the wilcoxon test differentiates from the t test so it can be used with ordinal variables. In other words why can't we use a t test for ordinal variables but can we use a wilcoxon ...
- 753
8
votes
1
answer
13k
views
When should I use `scipy.stats.wilcoxon` instead of `scipy.stats.ranksums`? [duplicate]
I've been using http://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.wilcoxon.html but then I realized that there is http://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.ranksums....
- 1,472
1
vote
1
answer
75
views
Which nonparametric test should I use
I am currently doing an experiment to test whether there is a significant difference between test results of a control group of steel bars of good shape and another group of corroded steel bars. I do ...
- 603
4
votes
0
answers
406
views
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. ...
- 41
8
votes
1
answer
972
views
Rank and z-transform instead of Wilcoxon?
Andrew Gelman in a recent post in his blog suggests using a rank, transforming the rank to a z-score, and then using parametric tests and tools instead of performing non-parametric tests. I never ...
- 5,387
15
votes
3
answers
5k
views
Why is the asymptotic relative efficiency of the Wilcoxon test $3/\pi$ compared to Student's t-test for normally distributed data?
It is well-known that the asymptotic relative efficiency (ARE) of the Wilcoxon signed rank test is $\frac{3}{\pi} \approx 0.955$ compared to Student's t-test, if the data are drawn from a normally ...
- 23.8k