Tagged Questions

1
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0answers
32 views

Two-way anova with interaction term: what is the point of a post-hoc test?

I have a statistics interpretation question. I've recently performed a two-way anova to identify an interaction term between my categorical independent variables (genotype + temperature) that ...
2
votes
0answers
39 views

Two uneven groups (101 vs 21) measured twice; what repeated measures ANOVA equivalent can help?

I have a question that I have difficulties in answering: I have two groups of patients tested twice at the same continuous variable. Group A=104 & GroupB=21. So two groups, one continuous ...
0
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1answer
41 views

Ranks test problem

This is a questions I got for homework in test planning and variance analysis. I apologize in advance for the way my professor phrases things :D I would love to hear hints or tips on how to approach ...
1
vote
1answer
37 views

Non-parametric test for 3 matched-pairs?

I showed a video to 3 groups, and they answered questions before and after the test. Control group watched it with no ads Group A watched it with ad A Group B watched it with ad B The sample is such ...
0
votes
0answers
113 views

Non-parametric counterpart of Nested Anova with unbalanced designed

0 down vote favorite Is there a non-parametric counterpart of Nested ANOVA with unbalanced designed? My data is not normal even after doing different transformations. Thus i could not use parametric ...
1
vote
1answer
296 views

Alternative to 2-way ANOVA when variances are unequal

I'm working on a question on 2-way ANOVA where there are 2 treatments and 1 blocking factor. The residual plots suggest unequal variance. What is another parametric or non-parametric alternative ...
1
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0answers
841 views

Non-parametric alternative for 2-way ANOVA

Suppose I have 2 independent variables whereby normal distribution can be assumed. However, there is unequal variance and interaction between the two factors is unknown. Could someone suggest an ...
2
votes
1answer
795 views

Non-parametric for two-way ANOVA (3x3)

My dependent variable is continuous, non-normal (skewed left according to Shapiro-Wilk test). I have two independent variables (treatment group by colour, food type). There are 3 levels within each ...
2
votes
1answer
517 views

Nonparametric alternative to ANOVA for testing the difference between several brand preferences

I have collected a data from about 200 customers on their brand preference of 5 international fast food chain shops. Each customer was asked to rank all the 5 brands from highest to lowest (5 for the ...
1
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0answers
107 views

What is the nonparametric variant of multivariate ANOVA with more than one one factor (and with interactions between factors)?

I analyze real data where assuptions of classical multiway (more than one factor assumed) MANOVA (more than one response variable) are not met (normality, equal variances). Is there any nonparametric ...
3
votes
1answer
127 views

How can I test for within-subject “consistency” across repeated measures?

I have a dataset with a clear question I want to answer, but I'm unsure of the best statistical approach to answer my question. Here's an example that matches the structure of my data: Let's say we ...
0
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0answers
296 views

Friedman's Anova on qualitative data in SPSS

I have some qualitative data and having trouble preparing the data before I perform the analysis in SPSS. My understanding of Friedman's anova is that the data must be ranked from lowest to highest. ...
4
votes
2answers
4k views

How to run two-way ANOVA on data with neither normality nor equality of variance in R?

I am working on my master thesis at the moment and planned on running the statistics with SigmaPlot. However, after spending some time with my data I came to the conclusion that SigmaPlot might not be ...
3
votes
2answers
583 views

General approach for non-parametric two-way ANOVA

Apologies for the almost text-book like question. I have a 2x2 design with fixed categories and a continuous response variable. If the variances are equal between groups (Bartlett test) and ...
1
vote
1answer
151 views

Can median polish be used for hypothesis testing?

I recently learned about the median polish method as a robust alternative to ANOVA for the purposes of fitting models to data. But, is there a way to test hypotheses using median polish, such as a ...
1
vote
2answers
419 views

Why would I use ANOVA instead of a Rank-Sum test?

A colleague of mine with little statistics experience is trying to perform an experimental evaluation of a computer program. He created a between subjects design and solicited test subjects. 11 ...
4
votes
2answers
203 views

ANOVA for non-normal heterogenous unequally replicated data

I need some advice on how to proceed with my data analysis. I have 3 groups (Archaea, Bacteria and Eukarya). Each group has unequal number of individual species (70, 651, and 244 respectively). Each ...
6
votes
3answers
2k views

Is there an equivalent to Kruskal Wallis one-way test for a two-way model?

If the model does not satisfy ANOVA assumptions (normality in particular), if one-way, Kruskal-Wallis non-parametric test is recommended. But, what if you have multiple factors?
3
votes
1answer
3k views

Pairwise comparisons after significant interaction results: parametric or non?

I've run a 2-way ANOVA on growth rate data (grams/day) with the factors of year type (good and poor) and site (A and B). Though the data themselves are non-normal and do not have homogeneous ...
4
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1answer
2k views

Friedman's test and post-hoc analysis

I am carrying out a statistical analysis for my research. I am using a Friedman's test with post hoc analysis. At present I am using the function ...
5
votes
1answer
611 views

Two-way robust ANOVA

My struggle with non-parametric methods continues... I'd like to apply a median polish instead of two-way ANOVA (normality and homoscedascity assumptions are violated, and $ n_{ij} $ are small, so I ...
5
votes
1answer
2k views

Which non-parametric test can I use to identify significant interactions of independent variables?

I have an experiment producing results (dependent variables) that don't pass tests of normality, thus I am testing hypotheses using non-parametric tests. My DVs are continuous, while my factors ...
6
votes
4answers
2k views

Multi-way nonparametric anova

I have to analyze a factorial design with five factors (one of them nested in another one) and numeric responses. I would like to perform a nonparametric ANOVA, but of course I can't use neither ...
3
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1answer
482 views

What software allows non-parametric repeated-measures multi-way Anova?

A previous user asked this question specifically for R. I'd like to know what, if any, other software can do this.
5
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3answers
5k views

A non-parametric repeated-measures multi-way Anova in R?

The following question is one of those holy grails for me for some time now, I hope someone might be able to offer a good advice. I wish to perform a non-parametric repeated measures multiway anova ...