Questions tagged [anova]
ANOVA stands for ANalysis Of VAriance, a statistical model and set of procedures for comparing multiple group means. The independent variables in an ANOVA model are categorical, but an ANOVA table can be used to test continuous variables as well.
22 questions from the last 30 days
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Bradley's liberal criterion
I'm reading an article where the authors utilized Bradley's liberal criterion to estimate the robustness of the F statistic in the context of post hoc tests.
The problem here is that they said the ...
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How to Analyze and Interpret Between and Within Variance in a Dataset with Measurement Errors?
I am analyzing air pollution levels across 5 firms. For each firm, I have daily air pollution measurements taken over 5 days. My goal is to evaluate the variability of air pollution levels between ...
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Can MANCOVA be applied for the following parallel factorial trials?
Good morning everyone, I have a question about the validity of MANCOVA for a project. I have a factorial experiment to optimize removal efficiency "Y", considering two factors (velocity &...
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What stats should I use? [closed]
I have a group of subjects all completing the same swimming time trials (6). I want to evaluate 1 variable from each trial using 2 different measurement methods, and then see how the measurements ...
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Computation question for ANOVA with matrices
I'm currently studying for finals and have come across this question that I'm having trouble approaching. The linear regression model is defined as always (in this particular scenario with 2 ...
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I want to compare my data, which are comparisons the "trimmed means" of 3 groups in ANOVA. Is this possible in SPSS? [closed]
Comparing "trimmed means" of 3 groups in ANOVA. Is this possible in SPSS? if not, how can i do that. In "R" the codes are so confusing and does not work
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When doing multiple ANOVAs, do I need to adjust the p-values?
I measured 12 blood parameters in 80 individuals and I know sex (F/M), season (start/end) and locality (A/B). So I have 12 continuous dependent variables and 3 independent variables, each with 2 ...
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What model for my data?
I have a problem where we want to compare 3 treatments (a standard one against 2 new proposals). For each treatment we produce 5 objects. Each object is then divided in smaller parts and from each ...
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Choose the right Statistical test in my case
I have a survey dataset where each participant answered 20 unique questions. I want to analyze the data statistically but am unsure which test to use: ANOVA, repeated measures ANOVA, or mixed-effects ...
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Post-hoc Analysis whith interaction but no main effects
I am reviewing a scenario where I have two factors (insecticide, herbicide) each with two levels (absent, present). There is no main effect for insecticide or herbicide, but there is a cross-over ...
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Nested design with fixed and random effects: Is my R model correct?
I am trying to analyze a nested experimental design in R, but I am unsure whether I am approaching it correctly. I have a following data:
Set
Sample
Repet.
Response
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1
1
y1
1
1
2
y2
1
2
1
y3
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2
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How much missing data in the output variable is OK when using Linear Mixed Models?
I have repeated-measures data, but due to missingness, I plan to use linear mixed models. My only predictor is Time, and my outcome variable is a Happiness Score measured quantitatively. The goal is ...
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How to retrieve main group effects from GEE in R (anova?)
I want to know if the outcome variable differs across three groups. As my data includes several family members, I use a Generalized estimating equations (GEE) model in R:
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Why does the f-statistic change between nested anova's?
My understanding of the p-values in an ANOVA table is that it gives the significance of an additional predictor in a sequence of increasingly larger models. So I would expect the first 2 rows of an ...
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How to approach a one-way ANOVA with SOME dependence?
I am looking to compare several groups using a one-way ANOVA. Each group is independent from one-another, but the samples within each group have some dependence to one-another (i.e. some (or all) of ...
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Can I use only the block section of a center composite design for optimisation?
So I designed an experiment with 6 variables to run sequentially in a supposed closed environment automatically. However during the switch from different blocks, something went wrong and now only the ...
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Multivariate (two-way/two-factor) ANOVA post hoc tests proper significance calculation method
I would like to get a proper justification for choosing one of the three of the various methods used to determine the causes of interactions in post-hoc procedures for multivariate ANOVA. I have ...
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Negative binomial GLM with interaction term...Anova warning?
I am running a seemingly simple model:
model<- glm.nb(PathogenLoad ~ Species*Lifestage, data = data)
The species variable has 3 levels and Lifestage has 2 ...
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Isn't it a problem to conduct post-hoc tests based on the overall p-value from ANOVA?
Let's say that after conducting an ANOVA, I get an overall p-value smaller than 0.05 (or whatever alpha level). Following that, I decide to conduct post-hoc pairwise tests to check the individual ...
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Is LMM a good alternative for Repeated Measures ANOVA with Missing Data?
Our study aims to assess whether there has been an increase in overall happiness among participants who used our interventions—such as dance classes, art classes, meditation, and other resources—...
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Comparing data at different locations over a time series
I have water quality data from sondes placed at different locations across a lake that collected every hour over the entirety of the summer. I want to know if there is a difference between the four ...
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No significance in omnibus test, but significant in EMM [duplicate]
I am trying to investigate the difference between the level of a protein in people with and without an injury.
The protein is a transformed variable, and normally distributed. I wanted to adjust for ...
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