Questions tagged [kruskal-wallis-test]
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.
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Statistical significance for REPEATED ordered categorical data
I have data of the following form:
Rating
1
2
3
control
0
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11
treatment
6
14
12
Where 1 is a plant of top quality, 2 is a plant of lesser quality that USED TO BE top quality, and 3 is a plant of ...
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Using Kruskal-Wallis to Detect Seasonality in Time Series
I am trying to write some code to automatically detect whether a time series is seasonal. I have been looking into using the Kruskal-Wallis test, as there are a few examples of this being useful ...
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Likert Scale - Statistical Analysis?
I have conducted a very large survey (n>10,000). I asked all participants a series of demographic questions (gender, ethnicity, educational background etc - all categorical). I then asked all ...
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Can I perform multiple Kruskal-Wallis tests with different explanatory variables against the same response variable?
My data is observational data, and that's made it all kinds of ugly, and I can't decide what statistical test is needed. I have one response variable, which is categorical (Species 1, Species 2, or ...
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Can I use Kruskal-Wallis test for dependent and fixed ordinal variables?
Can I use the Kruskal-Wallis test for data that has two columns of ordinal data (scales)? The first column has respondents' subjective evaluations of the product's price (dependent variable) on a ...
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Alternatives to the Kruskal-Wallis test?
I have determined malaria prevalence in 8 villages with household-level clustering.
As an initial test (basic descriptive statistics), what test (as the independence assumption of K-W is violated) is ...
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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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Should we stop to use kruskal function of agricolae package for post-hoc (multiple comparisons) tests?
Lot of people use the kruskal function of the agricolae package (R) to make multiple comparisons.
If they do so, it means that ...
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Is it possible to perform a comparison to a control group with a non-parametric post-hoc test in R?
Is it possible to perform a comparison to a control group with a non-parametric post-hoc test in R? I am familiar with various post-hoc tests such as Dunn and Conover, but I'm not sure how to ...
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Can I conduct a Kruskal Wallis test on 4 groups with very different sample sizes?
I have a paper under review where I conducted a Kruskal Wallis test in SPSS to compare 4 groups. Each group contains payments made by companies over one year, and ...
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Is this graph heteroscedastic and if so is Kruskal Wallis test invalid?
I'm new to stats and using GraphPad Prism9 to look at homoscedacticity of a Kruskal Wallis test. Just wondering if this is heteroscedastic because it's cone shaped to me? Also would this mean that the ...
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Kruskal-Wallis test when $k=2$
I have heard that Kruskal-Wallis test with two groups is equivalent to the Wilcoxon rank sum test, but I can't figure out how to prove it. Could someone please help me prove that under the condition $...
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Is is appropiate to use Mann Whitney's U to compare one group vs the others after a significant Kruskal Wallis AND significant post hoc tests?
Ok, so I have a very basic knowledge of statistics and I'm trying to get my dissertation done guided by books, internet tutorial and googling Q&A forums like this one.
I am comparing a ...
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Does a skewed distribution affect my kruskal wallis ANOVA?
I have the following data
Which is basically, a UserId, the place where he came from, and the Suffix (amount of templates that he saw). The context is that this dataset is from a chatbot sales bot.
...
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Appropriate Test for Two Independent Variables and One Dependent Variable
I have a dataset of bird foraging rates. I am interested in how two independent variables, SEASON and HABITAT, (both of which have two options: breeding/non-breeding, and urban/rural) respectively ...
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Is kruskall wallis appropriate here?
I have collected campaign finance data about donations individuals have made to 3 groups (A, B, C) between 2015 and 2020. Each donor has only donated to one group but some donors have donated ...
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The number of sample size in this case
I'm trying to compare three conditions (A, B, C). And I have a question about the sample size in this experiment.
There were 27 participants, and each participant listened to 20 songs for each ...
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Kruskal-Wallis nonparametric test for percentage data?
My study design includes: 4 groups of 6 observations per group. I have short and long survival group, each time 6 control “surrounding lung “tissues and 6 lung tumor tissues.
My first question would ...
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How to compare more than two matched medians
My sample consists of 30 patients.
These patients had three times of hormonal dose measurement:
Time 1, Time 2, ...
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Multiple comparisons problem in adjacent data comparison
I partitioned data by age like this:
first_data(0-1 years),
second_data(2-3 years),
third_data(4-5 years).
Each is not normally distributed.
I want to compare adjacent data only, that is first_data-...
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ANOVA vs Kruskal Wallis
I understand that ANOVA is a parametric test while Kruskal Wallis is a non-parametric test. My dataset is not normally distributed but heavily skewed (Skewness: 2.5, Kurtosis: 26.1).
Because of that, ...
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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 ...
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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 ...
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statistical test to distinguish groups effected by treatment
I have a set of 395 data points that are classified to 90 groups whose sizes range (1-30). For each data point I have two measurements taken in two different conditions - one being the control and one ...
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Why Pairwise Wilcoxon Test show differences between two alike groups but not whith the seemingly different one?
I have fruit weight data for 5 treatments, that doesn´t follow a normal distribution since it was measured with a kitchen weight scale (not enough resolution). Also, the data is unbalanced because ...
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Kruskal-Wallis DV/IV relationship
I have conducted a Kruskal-Wallis test in a bid to determine the impact of a student survey's rotated component on attendance. The attendance is ranked with discrete values from 0 - 4, and the ...
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Checking for significant associations between a mixed set of predictors prior to running a conditional random forest model
I am running a conditional random forest model using the party package in R, with the goal of quantifying variable importance (permutation importance) for 29 predictor variables. My response variable ...
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How to do pairwise comparisons for Kruskal Wallis test?
If the null hypothesis in the Kruskal Wallis test is rejected, How can we perform pairwise comparisons? Can we apply Dunnett's Test for that?
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How can I correct for multiple comparisons in two-way non-normal data (without using Bonferroni)
I'm struggling to carry out statistical analysis on my cell viability assay. The assay is widely used (it's called resazurin or alamarBlue assay), but I don't think it is analysed correctly in the ...
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Non-parametric MANOVA, (multivariate) Kruskal-wallis, or data transformation?
I have one IV (faculty) and multiple continuous DVs and wanted to do a one-way MANOVA. As MANOVA requires normal-distributed data, I plotted the DVs and saw that they are heavily long-tailed (keep in ...
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Non parametric test for control/ test dataset provenient from literature review
I have been working with a dataset that contains a pair of control/ test variable that represents the anthropization effect on water quality. This dataset was obtained through a literature systematic ...
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State-of-the-art nonparametric $k$-way ANOVA allowing heteroscedasticity
QUESTION: Can you recommend a nonparametric version of a multiway ANOVA that is also robust in the absence of homogeneity of variances? So, this is what I am looking for:
(1) Nonparametric ANOVA (no ...
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Run Kruskal-Wallis (and Dunn's Test) with multiple responses in R
I want to compare three groups with each other and have chosen the Kruskal-Wallis test and then the Dunn's test as post-hoc test.
If I have a data set like this:
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How to compare observed versus expected ratio data between two independent, unpaired groups with different sample sizes?
so I'm comparing the expected fitness of double mutant animals (based on independent, additive effects of each corresponding single mutant) to the observed fitness of the double mutant. The data is ...
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Experience with Kruskal-Wallis versus Zero-Inflated Kruskal-Wallis as nonparametric alternative to one-way ANOVA
I have a data set of 1 categorical predictor (4 levels) and one non-negative continuous response variable (listed as "aphidleaf in histogram). The response variable is not count data and the ...
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Kruskal Wallis Test with Random Effect?
I am trying to analyse the effect of season (autumn or summer) on frog sperm cell concentration (continuous, expressed as cells/ml). Because I don't know if there is an effect of male variation I want ...
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Interpretation of kruskal wallis test results
Hello I have run a kruskal wallis test to compare the median between three groups as in this picture below:
I know what median value and p value are but:
IQR is the spread of data but what is used ...
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Kruskal-Wallis test on data with heterogeneous variance and small sample sizes per group
I've been trying to figure out how to test (in R) if there are significant differences between the group means of my data because it seems to violate the assumptions of tests that do this (ANOVA, ...
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Statistical analysis - Shapiro-Wilk test?
I apologize if this question will seem odd, but I am quite new to statistical analysis.
I performed coinfection experiments with a total of 12 conditions, and I have 3 measurements per condition.
I ...
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Can the chi-square statistic in Kruskal-Wallis test be compared to determine the most appropriate to distinguish the groups?
I have a dataframe in R which format is similar as follows:
v1 v2 v3 group
1 3.5 100 a
3 5 200 a
10 5.5 150 b
8 7.5 210 b
4 4.5 300 c
9 2.5 200 c
...
My ...
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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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Using multiple mean tests instead of linear model
First, I would like to apologize because I'm a beginner in statistics and I'm surely confused on some points. This is one of my first statistic work doing for university.
I would like to explain a ...
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How can I explain signifcant combined groups in Mann Whitney U but no individual effects in Kruskal Wallis?
I am struggling to get my head around the concepts of my tests and how to explain them. Unfortunately we didn't recieve much in depth teaching about it on my course.
I have 4 variables, one is a ...
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Which Significance test to apply to compare number of occurences of multiple events across multiple groups?
Our dataset is composed of time-series data (recordings) collected for 18 different groups (test conditions G0 to G17). The number of recordings per group can vary (30-600). For each of these ...
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Dunn's post-hoc Test after Kruskal, 'which one is more effective?' after significant difference
Dunn's test yielded the result that there is a significant difference in revenue between group 1 and group 2 after Kruskal.
In classic one way ANOVA case, if the result is same as above, you see ...
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Appropriate statistical test to compare groups containing discrete data
I need to compare more than 2 groups, each containing discrete data (more specifically, integer numbers between 1 and 9). Shapiro-Wilk tests come back as significant for most groups, meaning the data ...
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showing significance of gender differences in control vs treatment groups
I have 4 groups with independent samples :
Female Control
Female Treatment
Male Control
Male Treatment
When I compare Control to Treatment within the same sex, I find that Female Control to Female ...
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Is it appropriate to remove biologically meaningless pairwise comparisons after Dunn test for a post-hoc(FDR) analysis for multiple comparisons? [duplicate]
I have four individual groups(A, B, C, & D)
Differences between the groups are being analyzed by the Kruskal-Wallis test followed by Dunn's test for multiple comparisons (dunnTest command in R). ...
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