Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [kruskal-wallis]

The Kruskal-Wallis procedure is a nonparametric equivalent of one way analysis of variance, used for comparing the location of three or more groups; it extends the two sample Mann-Whitney-Wilcoxon procedure.

0
votes
1answer
39 views

Which statistical test for my data?

(EDIT: question simplified) This is a basic question, since I am new to data analysis and statistics. I am carrying out a 2X3 factorial survey where participants are presented with a series of ...
0
votes
0answers
20 views

Is it correct that JMP has Mann-Whitney U for comparing more than 2 unpaired groups (instead of Kruskal-Wallis)?

To the best of my knowledge, the Mann-Whitney U test (also called Wilcoxon-Mann-Whitney) is for comparing only two unpaired groups, while the Kruskal-Wallis test is used for comparing two or more ...
2
votes
1answer
30 views

What is the point of a permutation F-test when all you need is one F-test for one-way ANOVA?

Say you have three groups, and each group has 5 observations. You can figure out if there is a significant difference between means with a simple one-way ANOVA. I read in my nonparametric book, one ...
1
vote
2answers
46 views

Normality vs normality of residuals

I am currently trying to perform a hypothesis test on the difference between four means. Initially I was trying to use ANOVA but then realised I may not meet the assumptions for this test and may need ...
0
votes
1answer
41 views

Reporting insignificant results using mean ranks

I have a number of non-significant results from a Kruskal-Wallis test and wondering the best way to report them. My independent variable is 3 categories: Group A: Uses product A; Group B: Uses ...
-1
votes
1answer
28 views

Statistical test to use to test mean equality given non-independence assumptions

In a survey conducted, 75 survey participants were asked to rate randomized keywords from groups 1-5. Every keyword belongs to a group and subjects were asked to rate each keyword. I would like to ...
0
votes
0answers
37 views

Kruskal Wallis test or Friedman for multiple preselected unmatched pairs

I am unsure whether I should use Kruskal Wallis test or Friedman's test in the following case, where I am required to use a non-parametric test while compensating for multiple comparison with a post ...
0
votes
0answers
11 views

How to test for differences between groups for ordinal outcome variables in SPSS?

I do not have experience with ordinal data, please help me out with my questions? I have conducted a survey which consists of 25 Likert-items, these items are all statements for certain conditions ...
0
votes
1answer
31 views

How can I calculate confidence intervals for epsilon-squared (Effect size for Kruskal-Wallis test) in R? [closed]

I'd like to calculate the confidence intervals for the epsilon-squared effect size statistic in R. Here is the code I'm using to calculate the epsilon-squared value: ...
2
votes
0answers
42 views

Should ANOVA be used when the dependent variable is an integer, such as a count of items? [duplicate]

I have data for a dependent variable, DV, representing a count of objects, with a range from 0 to 6 (sample size 450), slightly left skewed with a mode at 4: Furthermore, I have a single categorical ...
1
vote
0answers
29 views

Comparing 3 groups at 2 time periods

I'm analysing a dataset and comparing three zones at two points in time. The data in question is: Hourly sightings of wild fish (CPUE) In one of three adjacent zones (A, B, and C) During the ...
3
votes
1answer
65 views

Mann-Whitney U test or Kruskal Wallis test for comparing median of two groups?

I know that Kruskal Wallis test can be used to compare median of two or more groups (e.g. see this link: https://www.statisticshowto.datasciencecentral.com/kruskal-wallis/ ), and that Mann-Whitney U ...
0
votes
0answers
17 views

Using Multiple Comparisons for Kruskal Wallis Follow up analysis

I am performing the Kruskal Wallis test on ~100 samples and wish to group statistically ‘similar’ samples together. The method I am using is described in Andy Field’s ...
0
votes
0answers
23 views

Pair-wise ANOVA or non-parametric comparison

I'm doing an experiment with 7 groups (batches) of 12 measurements of a certain chemical, where one group (b0) is considered the baseline case. The research question is to find out which groups have ...
1
vote
3answers
241 views

Meaning of chi-squared in R Kruskal-Wallis test

I have a simple question to ask, I think it was not covered in other questions. I am running a Kruskal-Wallis test in R, using the function kruskal.test. The output gives me the p-value and a chi-...
0
votes
0answers
41 views

Non-parametric test for interaction effect

I have a relatively small data set with quality ratings (dependent var), for different compression methods (independent var 1) applied to different types of video (independent var 2). My first ...
2
votes
0answers
79 views

ANOVA with post hoc for non-normal data with unequal variance

I have 200-some variables with 25,000 observations in each of 4 categories. For each variable individually, I need to identify where we have variability between categories. Therefore, I need an ...
0
votes
0answers
23 views

Is my analysis approach and decision valid?

I'm busy with a class assignment and I would appreciate a second pair of eyes on my analysis approach. A part of me feels that I'm overthinking this or have done an unnecessary test. Context: Use 4 ...
0
votes
0answers
12 views

Find joint distribution for two different cases Kruskal Wallis

I'm a bit stuck with my homework in a subject called "Non-parametric Statistics". The task is related to Kruskal-Wallis test. The task is as follows: Let's look at the comparison of 3 independent ...
1
vote
0answers
17 views

Can I use both parametric and non-parametric tests?

I have 3 variables, A1, A2 and A3 A1 is temperature A2 is month A3 is location A2 has 2 months - March and May. A3 has 2 cities - Chennai and Dubai. My data is ...
0
votes
0answers
68 views

Is it okay to use non-parametric tests on normalized data?

I'm doing experiments with 3 conditions: A, B, and C. I have done the experiment 3 times, so each condition gets 3 values for a total of 9 values. Each value is actually an average of 5 measurements. ...
0
votes
1answer
47 views

multiple comparison with controls - kruskall wallis or mann whitney + bonferroni

I have a test group and two control groups. I would like to compare: test vs control group 1 test vs control group 2 and I don't need the result from control group 1 vs group 2. Therefore, in this ...
4
votes
2answers
215 views

Is it possible to calculate a confidence interval related to a significant p value from the kruskal wallis test?

I have run the nonparametric Kruskal Wallis test with pairwise comparisons in SPSS to understand if my 3 groups of survey participants were different in their responses to a range of 5 point ordinal ...
1
vote
0answers
616 views

Wilcoxon Rank Sum test unequal sample sizes

I am comparing two sets of data using the Wilcoxon Rank Sum test. Although the distributions appear to be quite different, the p-value is quite high (0.344). This is the line of code being used for ...
0
votes
0answers
21 views

comparison of multiple groups when the dependent variable is a percentage

I am measuring the proportion of different types of bacteria killed by 4 different antibodies (simplified for illustration) ...
1
vote
0answers
31 views

Significance testing on two groups (distributions) of many binomial distributions

Basically I have two (or more) different success probability generating distributions. In other words, there are two (or more) different (non-normal) distributions, which realize success probabilities ...
1
vote
1answer
265 views

how to measure the correlation between non-normally distributed numeric variable and nominal variable?

I have two nominal variables and some numeric variables. The first nominal variable is a binary one. I want to measure the correlation between this binary variable and the other numeric variables. ...
1
vote
0answers
33 views

For my data, should I use a Kruskal Wallis or one-way ANOVA test?

I read through some literature online and did some investigating on my data and the type of scales my data represents. In my data set, I have my independent variable called ASA status (this is a ...
1
vote
1answer
98 views

Are the results of my paired tests false positive?

I am dealing with a strange situation which I hope you can come up with a solution. I have 3 pared group(n=7 for each) which I tried to see if they are significantly difference and if so, in which ...
0
votes
1answer
71 views

Test statistic for follow up procedure (stepwise step down) of Kruskal Wallis

When conducting a Kruskall Wallis test, it is possible to follow up the procedure with a post hoc test, looking for homogeneous subsets. My question is which statistic is used to perform this ...
0
votes
1answer
15 views

What is the appropiate Non-parametric test for study with 3 conditions?

The IV has 3 separate conditions & the DV measures Pre & post scores (ultimately to see what condition has the biggest effect on the scores - if there is any). The data is non-parametric- ...
1
vote
0answers
40 views

Kruskal Wallis H test

I am doing a Kruskal Wallis H test, it looks like I am getting a significant difference between the non-vegetarian group and the vegan group. But not with the semi-vegetarian group and vegan group. ...
0
votes
1answer
12 views

Accounting for measurement Bias across manufacturers and multiple treatments

I've been trying to figure out the appropriate statistical approach for the following problem from work (simplified here): I've got 5 manufacturers of a drug and each manufacturer makes their own ...
0
votes
0answers
213 views

Dunn's test of multiple comparisons

From the documentation page for the R function dunnTest from the package FSA: Performs Dunn's (1964) test of multiple ...
0
votes
0answers
29 views

Testing 3 Kruskal Wallis on 3 datasets that each has 3 treatments

I am not that experienced, but, I read a lot and seems am stuck to know if what i am doing is right or not. I have 3 datasets that each were initiated based on session duration. The 1st dataset has ...
2
votes
1answer
456 views

Understanding hypothesis testing (Kruskal Wallis, Mann-Whitney) when there are tied values

tldr: In Python's Scipy stats modules, the kruskal and mannwhitneyu functions will both raise an error if called with only ...
1
vote
1answer
105 views

Two-Way Non-Parametric Test for Non-normal Data?

I have an unbalanced design with two factors, gender and site. I'm trying to test for differences in a size variable. Levene's test reveals that the data has equal variances. However, log transformed ...
1
vote
0answers
24 views

Non parametric tests for relation/association between variable

What could be an appropriate test for checking whether there exist any relationship between Net Promoter Score ( Categorical in nature with 0 meaning detractor, 1 meaning Neutral, 2 meaning Promter ) ...
1
vote
0answers
19 views

Is it ok to re categorize my variables this way?

I have a 2^3 factorial design, where the dependent variable is binary, and the three independents are binary and I care about interactions. I've seen that you can use logistic regression, but I feel ...
0
votes
0answers
17 views

How can I test the effect of a continuous IV (as well as other IVs) on an ordinal DV?

I have two instruments: a test, and a survey. Each participant has a test score, out of 240 (or a percentage out of 100%, it doesn't really matter.) The survey consists of 5-point Likert-scale ...
1
vote
1answer
303 views

About Kruskal-Wallis, Mann-Whitney U and multiple comparisons correction

I have 5 independent samples which I want to compare, to define if there are significant differences in the distribution of values across samples. The samples' sizes are: 4562, 1116, 314, 151, 77 I ...
0
votes
1answer
119 views

Kruskal-Wallis and non significant post hoc test

I am running Kruskal-Wallis tests in SPSS to compare answers to Likert items among 3 (variable 1) and 4 (variable 2) groups. I am not running ANOVAs because assumptions of normality and ...
1
vote
0answers
46 views

Statistical tests, when data are not normally distributed & variance is not equal

I have a data with two variables - one variable is quantitative, and one is nominal (4 categories). I ran the normality tests and it turned out that this quantitative variable is not normally ...
1
vote
0answers
12 views

Comparing 4 groups of unequal sizes and non-normal distribution

I have 4 groups of students. Each student was asked to give us the number of reports they wrote through the semester.The 4 groups have n ranging from 5 to 250 ...
1
vote
0answers
748 views

Is it possible to use a Kruskal-Wallis test with multiple independent variables?

For my study, I'm investigating whether student's scores in a task (expressed as a percentage between 0-100%) influence their responses to a survey. The survey has 19 questions, and they're Likert ...
2
votes
0answers
38 views

Is Kruskal-Wallis the right test?

I'm writing a research protocol and trying to work out the right test. Is there a significant difference between the success rate (dependent variable, ratio data) for different repair materials (...
0
votes
0answers
69 views

Parametric vs non parametric tests for Likert items?

I have conducted a survey and am now trying to figure out how to analyse the results. I have a series of 6-point Likert items, which I have coded like this: -3 Strongly disagree -2 Disagree -1 ...
1
vote
0answers
63 views

Kruskal-Wallis test for showing features can discriminate the classes

I'm working on a problem for classifying 3 gestures using the EMG signals obtained from muscles. Each of the gestures has 6 trials of around 6-7s duration. Each trial is divided into multiple ...
0
votes
0answers
31 views

Non-parametric, 2-way ANOVA with different group sizes? [duplicate]

I have five cohorts I want to compare, initially with one factor as measured by a test. I was going to use a one way ANOVA, however discovered that the distribution was not normal, so was directed ...
1
vote
1answer
366 views

Kruskal-Wallis vs Jonckheere-Terpstra Test

If we're doing a Jonckheere-Terpstra Test and a Kruskal-Wallis test at the same significance level, which one is more likely to reject the null hypothesis when it is actually true? From my ...