Questions tagged [manova]
Multivariate ANalysis Of VAriance (MANOVA) is a generalization of ANOVA for the case with several dependent variables.
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Multivariate multiple regression in R
I have 2 dependent variables (DVs) each of whose score may be influenced by the set of 7 independent variables (IVs). DVs are continuous, while the set of IVs consists of a mix of continuous and ...
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How to interpret type I, type II, and type III ANOVA and MANOVA?
My primary question is how to interpret the output (coefficients, F, P) when conducting a Type I (sequential) ANOVA?
My specific research problem is a bit more complex, so I will break my example ...
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Differences between MANOVA and Repeated Measures ANOVA?
What is the difference between a repeated measures ANOVA over some factor (say experimental condition) and a MANOVA?
In particular one website I stumbled across suggested that MANOVA does not make the ...
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How is MANOVA related to LDA?
In several places I saw a claim that MANOVA is like ANOVA plus linear discriminant analysis (LDA), but it was always made in a hand-waving sort of way. I would like to know what exactly it is supposed ...
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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 ...
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Post-hoc tests for MANOVA: univariate ANOVAs or discriminant analysis?
I am using a MANOVA test to compare nine different dependent variables (from neuropsychological and neuropsychiatric assessment) between three groups. The output shows a significant influence from ...
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MANOVA and correlations between dependent variables: how strong is too strong?
The dependent variables in a MANOVA should not be "too strongly correlated". But how strong a correlation is too strong? It would be interesting to get people's opinions on this issue. For instance, ...
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What is the null hypothesis of a MANOVA?
Background
In order to analyze differences in some continuous variable between different groups (given by a categorical variable), one can perform a one-way ANOVA. If there are several explanatory (...
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Is there a generalization of Pillai trace and the Hotelling-Lawley trace?
In the setting of multivariate multiple regression (vector regressor and regressand), the four major tests for the general hypothesis (Wilk's Lambda, Pillai-Bartlett, Hotelling-Lawley, and Roy's ...
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Is VAR a MANOVA with auto regression?
What are the differences between VAR (vector auto regression) and MANOVA?
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Is it okay to perform PerMANOVA on PCA values?
Is it acceptable to first perform principal components analysis on a dataset, and then use permutational MANOVA on those principal components values, rather than on the original values in the dataset? ...
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Why is it rarely reported in papers which type of sums of squares is used in Anova results?
Following my short experience in statistics, it seems that the type of sums of squares (type I,II,III,IV...) used in getting ANOVA results could make a dramatic difference in test results (especially ...
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The way PERMANOVA handling continuous explanatory variable
I have read some tutorials which explain the mechanism behind PERMANOVA, e.g., enter link description here. Based on the tutorials, my understanding is PERMANOVA can only handle categorical ...
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How to do MANCOVA in R?
I have two groups of persons, GRP0 and GRP1, on which I measured three continuous variables: VAR1, VAR2 and VAR3.
I would like to use Mancova in R with:
- VAR1, VAR2 and VAR3 as outcome variables
- ...
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How can MANOVA report a significant difference when none of the univariate ANOVAs reaches significance?
I would just like to ask if it is normal for the values from my multivariate tests to be significant but for the values from my univariate tests of between-subjects effects table to be insignificant.
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What is the intuition behind (M)ANCOVA and when/why should one use it?
As per my understanding here's the what/why/when of the following hypotheses tests in a crude sense:
t-test: Used when comparing means between two samples
ANOVA (one way): Used when you have one ...
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MANOVA as protection against Type I errors
OK, so I have absolutely scoured the internet, and it appears that there is consensus (among people who really care about Type I error) that doing a MANOVA before doing multiple ANOVAs does nothing to ...
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MANOVA when sample size is smaller than the number of DVs
I need to compare $16$ quantitative variables, measured for two groups, A and B. I thought of applying MANOVA. However, there are only $4$ and $9$ cases for groups A and B respectively. I looked for ...
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Many dependent variables, few samples: is this an example of "large $p$, small $n$" problem?
"Large $p$, small $n$" typically refers to "many independent variables, few samples".
In my case, I have $1$ independent variable, $300$ dependent variables, and $n < 20$ samples.
Thus, my case ...
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Does summary.aov() of MANOVA object adjust for multiple comparisons?
I performed a MANOVA analysis in R, testing if two populations differ based on their multivariate phenotype, comprising 16 measurements. I then used the summary.aov() function on the MANOVA model to ...
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Choosing between a MANOVA and a series of t-tests when comparing two groups
I have to analyze the data from a study in which two groups of subjects (total sample $n = 30$) were tested on 4 cognitive tasks, all related to executive functions. For each task, I have accuracy ...
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How to read the output from MANOVA?
I'm testing if/how the two factors C and V affect the dependent variables fric and ...
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MANOVA with unequal sample sizes
I have data for 352 response ratings that have been categorized as "Low," "Medium," and "High." I would like to compare the differences of five variables across the three categories to see which ones ...
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Permutational MANOVA and Mahalanobis distances in R
In this paper
Anderson, M.J. (2001). A new method for non-parametric multivariate analysis of variance. Austral Ecology, 26, 32–46
I found very useful MANOVA approach that can, to some extent, ...
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How is MANOVA a case of the GLM?
It's easy and convenient to teach students the following regression equation
$$
Y=\beta_0 + \beta_1X_{\text{(continuous)}} + \varepsilon \\
\text{where }\varepsilon\sim\mathcal N(0, \sigma^2)
$$
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T-tests, manova or logistic regression - how to compare two groups?
I'd like to check whether women and men differ on those five variables, that can be correlated with each other. The groups are also not equal with 589 females and 293 males.
The solutions that come to ...
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MANOVA multiple comparisons with equivalence testing
For a MANOVA with $n$ variables, I would like to do pairwise comparisons between $k$ levels for one of the variables.
What is the suitable method to adopt for ...
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Significant output in Levene's test for equality of variances in MANOVA; what to do?
I want to perform a MANOVA in SPSS as follows: i have a independent variable that consists of three groups (- of which the group sizes are not equal), and six dependent variables.
When checking the ...
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Understanding MANOVA in case of a single predictor
I'm trying to understand the statistical analysis I saw in a clinical study. They measured performance of 3 groups of subjects with a series of performance measures (A, B, C, ..., N). The objective ...
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Kruskal Wallis or MANOVA
I have to analyse 8 independent variables (IV) toward 8 dependent variables (DV) in my research. The IV is nominal while DV are ordinal (Likert-scale). I run the normality test and the result is zero (...
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Why is it possible to have a non-significant MANOVA but multiple significant univariate ANOVAs?
The only source I have for this being possible is this wikiversity page on MANOVA, but it does not explain why it is possible.
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Is Repeated Measure MANOVA appropriate here?
I have data on the yearly number of doctor visits for patients from 2020 to 2022, along with characteristics associated with these visits. During each visit, patients are asked questions about their ...
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Assessing group differences on multiple outcomes
I have one independent variable with two levels: Gender (Male and Female),
and dependent variables will be composed of three test scores: Impulsivity, Assertiveness, and Social Desirability.
My ...
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Why is Pillai's trace equal to partial eta squared in a repeated measures MANOVA (profile analysis)?
I conducted a repeated measures MANOVA using the GLM command in SPSS, with one between-subjects IV (two levels) and 10 DVs (repeated measures). According to Tabachnick and Fidell (Book: Using ...
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How to perform a MANOVA with a random effect in R?
I performed an experiment where I raised different families coming from two different source populations, where each family was split up into a different treatments. After the experiment I measured ...
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Over enthusiastic MANOVA in R
In recent research I pursue a MANOVA model on a dataset comprised of 50 measured characters and several grouping factors that I need to test. When I use something like this
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Can I use both paired and unpaired t test in one study?
Is it possible to use both unpaired and paired t test in one study since I plan to both test the effect (pretest & posttest) in each participant and compare the results between the non-randomized ...
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Why do the results of a MANOVA change when the order of the predictor variables is changed?
So, for example, using the Iris data and treating iris species as the predictor variable and sepal length, sepal width, petal length, and petal width as the dependent variables we get MANOVA output ...
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Multivariate differences between groups controlling for one factor (MANOVA)
I have a sample of 100 participants who have scores on 5 different variables (V1-V5). Some participants took part in a workshop, others did not.
I am interested in investigating the influence of ...
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Tutorial for performing Contrasts for MANOVA
Context
I have a multivariate dataset with a test group and three control groups.
I was thinking that the best way to determine if and how the test group differed from all of the control groups would ...
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What is the reason behind the name "adonis" (for permutational MANOVA)?
Does any one know why Permutational Multivariate Analysis of Variance Using Distance Matrices (PERMANOVA) is also called adonis?
See
https://www.r-bloggers.com/adonis-permanova-assumptions
or
http://...
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When to interpret multivariate tests when performing repeated-measures ANCOVA?
Yesterday, I ran a repeated-measures ANCOVA. The purpose was to determine the usability of two computer systems, call them 1 and 2. Each subject completed three (conceptually different) tasks, call ...
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Test(s) For Comparing qPCR results / ΔΔCт values
To be clear, I'm talking about real-time polmerase chain reaction (qPCR), not Principle Component Regression. Though from a company selling qPCR reagents, here is a good walk-through of the ...
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Consequence of violating independence assumption of ANOVA
I would like some help with the following problem.
I have 40 subjects. On each subject I take a measurement at 25 body
sites. The measurement is a continuous variable that varies between 0 and 1 and ...
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MANOVA with variables from different datasets
I conducted several experiments where I have one underlying independent variable (tree species, IV). Each of these experiments gave me one dependent variable (DV), like bark pH, rugosity or the water-...
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What is the explanation of the difference caused by the order of variables in anova for the concrete example in R?
I wonder the real reason behind the difference in results of the two anovas that use the same covariates. However, the results are different.
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How can MANOVA report a non-significant p-value while LDA results in perfect separation of two groups?
I am new to statistics and currently got a dataset which contains $80$ dependent variables and $1$ independent variable with $2$ groups. MANOVA reports a $p$-value of $> 0.6$ on this dataset. But ...
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Difference between MANOVA and two-way ANOVA
I have read the articles of both of these statistical methods on wikipedia, and as far as I can tell they are used in the same cases. I could not tell in how far they work the same way, since the two-...
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Is this a proper use of mixed modeling?
I admit I'm fairly new at statistical modeling and so I'm not confident in the method I am using.
Using LC-MS/MS, I am monitoring the degree of post-translational modification of specific peptides by ...
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How to follow up a factorial MANOVA with discriminant analysis?
This is a follow-up to to my previous question: How can MANOVA report a significant difference when none of the univariate ANOVAs reaches significance?
I have two IVs with each having three levels ...
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