# Questions tagged [friedman-test]

A non-parametric test for the equality of >2 dependent groups.

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1 vote
43 views

### Can a Friedman's ANOVA be used for groups of different size?

The independent variable in my data is verb class: I have got four verb classes, each consisting of ten verbs. The dependent variables are accuracy (either 0 - incorrect or 1 - correct), and reaction ...
26 views

### 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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22 views

### Statistical Significance Testing for Nested Cross-Validation in ML Experiment

I am currently working on an ML experiment where I use a nested 5-cross validation procedure and obtain a NDCG@10 scores for each test user. I am comparing 6 different ML algorithms and have data for ...
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1 vote
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### What Statistical test to use on my project?

I am very confused about what kind of statistical test to use in RStudio on my project, I have measured the mean salinity for 3 levels of population density (low medium and high) across 6 months (...
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### What if using Friedman test on dependent variable that is nominal data?

I have a group of 30 participants who did a test for three times. Each time, The independent variable was changed and the participants reported their answers (dependent variable). The independent ...
72 views

### How should I analyze data that is paired and also repeatedly measured?

I have data collected from the same subjects (n=10) over 11 days, with measurements taken under two conditions each day: immediately after training(D0) and 30 minutes after training(D30). The data is ...
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### Identifying the type of missing data and the post hoc test that can be carried out for Skillings Mack test

I have a non-normal paired sample dataset. Each row represents a dog that has been tested for an experiment. Each dog was provided with three cues (treatments): 5s cue (aka only face cue), vocalone (...
1 vote
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### Alternative to Nemenyi posthoc test that can use variance

I am applying statistical tests from paper "Statistical Comparisons of Classifiers over Multiple Data Sets" J. Demsar (link) in my own work. However, variance is pretty important, since ...
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### What test should I perform given repeated measures of one subject in three time periods?

I have data that represents the measurements of the concentration of PM particles in the air at different times (every hour of every day from 2018 onwards), and I am supposed to test whether the rules ...
• 101
18 views

### Friedman test for small sample single arm trial?

I am looking at a single arm clinical study with a small sample size (n=14), where each patient was assessed 5 times (weeks 1-5, once a week). I have constructed linear models to see if the change-...
1 vote
87 views

### Is there any post-hoc test for multiple comparisons after conducting the Friedman test by two group using a preference ranking questionnaires?

I have this dataframe: group1<- matrix(c(rep(1,5),rep(2,5),rep(3,5),rep(4,5)), ncol=4) group2<- matrix(c(rep(4,5),rep(3,5),rep(2,5),rep(1,5)), ncol=4) I ...
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### What is the most common Nonparametric Global Test of Difference for Repeated Measure?

The experiment goes like, there are two different machines, Machine_A and Machine_B and a Technician. The machines have the same purpose which is for measuring a continuous quantity (be it weight, ...
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### Is there a method bias when I prefer a specific post-hoc that shows a significance after significance in test of difference in groups?

I'm working to see if a machine does better than a worker in terms measurement (by having a measurement from an expert be the control). So my dataframe contains the Measurement Value, Measuring Device,...
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### Which test in this case ? Friedman not possible

I have done a benchmarking of multiple learners on multiple tasks with nested CV (inner loop : CV 3F, and outer loop : CV 3F). My datas have 1052 observations and each task have 10-12 features. I ...
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206 views

### What is an appropriate post hoc test after the Friedman test?

I've read several posts related to this, but I'm not sure. so I'm posting the question in case it's redundant. I have been conducting an experiment using a within-subject design, comparing three ...
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1 vote
38 views

### Why is my Friedman posthoc test said to be "true" with a p value of 0.06?

I used the function friedman.test to test for differences between multiple conditions and then used friedmanmc as a posthoc test....
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74 views

### 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, ...
20 views

### Why is my result significant when there is no difference between means?

I have run a Friedman's test in R and it has given me the following result: ...
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588 views

### Alternative to Friedman Test in R

I am trying to run a Friedman Test in R with a repeated measure, however, my data do not qualify as an unreplicated complete block design. I am wondering what ...
1 vote
1k views

### Error when conducting a Friedman Test in R

I am trying to run a Friedman Test on some data in R. I would like to measure a 3-way interaction with a repeated measure. However, I keep getting a persistent error message when I run the code and ...
1 vote
104 views

### Hypothesis Test for Ranked Preference?

I am conducting a survey where people are required to rank 3 different designs from 1st to 3rd. For example, there are 3 designs - A, B and C. Participants are required to rank them in order of ...
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1 vote
92 views

### Calculate CI for chi-squared of the Friedman test in R

I have a dataset (not normal distribution) with repeated measures over time. As such I was planning to use the Friedman.test in R: friedman.test(dash ~ time | nr) ...
1 vote
56 views

### Clustered data and the Friedman test

Good morning, I am performing a risk factor analysis of the individual and household-level factors associated with Plasmodium infection in individuals located in 8 villages in Cambodia. I have ...
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2k views

### Post-hoc tests after Friedman test

In Statistical Comparisons of Classifiers over Multiple Data Sets (p. 12) Janez Demsar suggests to use the Bonferroni-Dunn test as a post-hoc test after the null hypothesis of an initial Friedman test ...
1 vote
109 views

### Trouble interpreting Friedman Test for 3-way repeated measures ANOVA

I would like to use a Friedman Test as a non-parametric alternative to a 3-way ANOVA in RStudio. I would like to measure how 'cl_conc' (Response Variable) is affected by 'soil_type' (Fixed Effect #1 - ...
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### Friedman test_multiplicity

I'm performing Friedman test to see if there is a difference between 8 treatments, then if it is significant I'll do Wilcoxon signed rank test to see which pair is significant. I wonder if I should ...
1 vote
60 views

### Repeated Measures, or just measuring the same thing, repeatedly?

I understand what "repeated measures" denotes - given a set of subjects, if each subject receives more than one treatment, we call this repeated measures, or "within subjects." But ...
60 views

### Analyse ordinal data between subjects

I have two groups of participants, group 1 looked at four images under condition 1, and group 2 looked at the four images under condition 2. I want to see whether the condition influenced the order in ...
1 vote
767 views

### Friedman's test and unequal sample sizes

I have movement information from 4 animals across different moon phases. I want to compare if their movement (eg. distance traveled per night) varied among different moon phases. However, I do not ...
1 vote
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### How does the Friedman test extend the sign test?

Every book/article claims this as if it's self-evident, but I have a hard time figuring out why. How do you get from the sum-of-squares style statistic of Friedman to the difference statistic involved ...
1 vote
277 views

### Kruskal-Wallis versus Friedman - Paired data, but not repeated measures/blocks?

I'm trying to compare the difference in behaviour of an animal with no enrichment to the same animal with two (or more) types of enrichment. (Total active behaviours before/total active behaviours ...
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1 vote
618 views

### Friedman Test not working. Is this the appropriate statistical test?

I am trying to determine if the mean distance between animal pairs changes across months. According to a Shapiro Wilk test, my mean distance measurements are not normally distributed. Due to this, I ...
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### Compare mean of subsamples between groups

I am going to collect quantitative data for two groups that I would like to compare. I have done a two sample t-test on some preliminary data and found a significant difference, but I don't think that ...
1k views

### Effect size measure for post-hoc tests after nonparametric tests: Alternatives to calculating r from z score?

I've calculated Friedman's tests for my data and want to report an effect size with the individual post-hoc tests that followed on from the statistically significant Friedman's test. I use the formula ...
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### Which ANOVA / non-parametric alternative should I use?

Apologies if this is a really simple question but I cannot work it out. I am trying to find out if year and/or location influence the amount of insects caught. Insects are measured in grams per 10km2. ...
451 views

### Which statistical method can be used to compare the values of the same variables measured from different views?

I got a biological data set, where I need to run a statistical analysis on. The data was created on a mass spectrometer and contains the intensity values for around one hundred lipids. The analysis ...
44 views

### Compute Exact Null Distribution for Friedman Statistic

Problem Statement: If there are no ties and $b=2,\;k=3,$ derive the exact null distribution of $F_r,$ the Friedman statistic. Note: This is Exercise 15.35 in Mathematical Statistics with Applications, ...
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35 views

### What test to perform on my complicated data...?

I have data that looks like this: I'm trying to analyze time and num_collisions. Subjects completed each combination of device/rho/lam/hmd x 6 trials [within subjects design, repeated trials] There ...
1 vote
481 views

### Not sure what test to run to compare the proportions of a count outcome across a variable with 5 levels, between two groups (using R for analyses)

For a case-control study that I've conducted I've measured how many times a count outcome (count_outcome) occurred in each of 4 areas (...
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1 vote
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### An a posteriori test to determine non difference across >3 groups given a skewed continuous variable of interest, as an alternative to a Friedman-test

Given a set of items of which each item is once measured using a computative model, each time under a different condition, what is the best way to quantify the magnitude of difference between ...
1 vote
119 views

### How can we prove that kruskal wallis test and jonckheere test is equivalent to wilcoxon rank sum test?

How can we prove that kruskal-Wallis test and Jonckheere test is equivalent to Wilcoxon rank sum test when k = 2? And how can we prove that Friedman test and Page test is equivalent to sign test when ...
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32 views

### Finding out the best experimentalist based on statistical analysis

There are $m$ students in a laboratory. Each student is assigned the same task, which is described below. i). $n$ unknown standards are given to each of them. ii). Each standard has to be analyzed $p$ ...
1 vote
761 views

### Friedman's test is very significant, but its post hoc comparisons are not significant

This post does not include an answer for my question. I have perform a Friedman test on a results obtained by several methods on multiple datasets, as described in this paper: "Statistical ...
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1 vote
514 views

### Should I rank my data before doing post hoc Dunn test?

I am trying to compare multiple algorithms using the Friedman test and post hoc Dunn test. I know that we should use the rank of our data before performing the Friedman test, but should we rank the ...
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1 vote
567 views

### Should I use Friedman test or Mixed Model for my data in R? Nested or not?

I have my Response variable which is Proportion of Range Exposed to extreme events for terrestrial mammal species in the future. More clearly, it is the Difference of Proportion of Range Exposed (DPRE)...
1 vote
26 views

### Every time I run a statistical test, my n-value is doubled

I just finished collecting data for a small study with a within-subject design looking at caching behaviour and how it can be affected by a bird's surroundings. My study had three experimental ...
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447 views

### Statistical significance test for 5-fold cross validation on a single dataset

I have used stratified 5-fold cross validation to generate five data folds to compare several (N) deep learning models on a single dataset. Now, I have the fold-wise test accuracies for all of the ...
57 views

### Kruskal-Wallis test for ranking data

I have a complex experimental design where there are 3 groups, and in each group, a ranking/comparison is made between items (list of items). Each ranking is associated with 9 measurements on a 5 ...
1 vote