"post-hoc" refers to analyses that are decided upon after the data has been collected, as opposed to "a priori".

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Statistics Test Question - Help needed! [on hold]

I am really terrible at statistics and basically don't even know where to begin on answering these. Any help would be appreciated. I've googled but there is some much info that it confuses me and I ...
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9 views

Multiple Regression: 3 groups for IV, post-hoc equivalent?

I would like to test the following: DV - Brain volume IV - Participant Group (Patient with Mild Symptoms, Patient with Severe Symptoms, Controls) Covariates - Age, Gender, IQ I wish to use ...
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1answer
24 views

Same result for post-hoc test and probit regression

I am getting the exact same results for a probit regression and post-hoc tests (simultaneous tests for linear hypotheses) - is this because I have used a dummy variable in the probit model and so it ...
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56 views

Simultaneous tests for general linear hypothesis question

I have run a probit regression and am now trying to run post-hoc tests. I am trying to compare differences between a 3 level factor variable. I am confused about the difference between running a ...
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1answer
13 views

post-hoc test for betareg model R

I'm currently analyzing a dataset about quality of fodder. The data for e.g. crude protein content are given in %, I don't have absolute values. Because of the data structure (I don't give you the ...
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117 views

It's all in the family; but do we include the in-laws too?

Suppose I have an experiment with two or more factors. An overall ANOVA is constructed, and then we follow-up with two or more sets of post hoc tests, say multiple comparisons. My question is about ...
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2answers
61 views

lsmeans (R): Adjust for multiple comparisons with interaction terms

I have a lsmeans problem in R. I want to do a post-hoc analysis of an interaction, similar to examples provided in the lsmeans documentation. I am puzzled by the fact that the p-values are the same ...
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12 views

Post-Hoc Chi-Sq test - conclusions drawn from comparing individual categories

My question is very similar to this one: (Post hoc $\chi^2$ test with R), but I'm still confused, and tried to provide as much detail as possible. I have two categories of students: Domestic and ...
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14 views

Contrasts / Post Hoc Tests for three way repeated measures ANOVA

I have three factors A B and C with 2, 2 and 3 levels. A and C have significant main effects, B is not significant, interaction A*C is significant, the others are not. Now I want to know how to ...
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1answer
12 views

criteria for choosing a post-hoc tests

After eg. ANOVA there are several post-hoc tests out there (e.g. Tukey, Bonferroni, etc.) but what are the criteria for choosing one over the other? If one is more conservative, shouldn't we use it ...
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1answer
17 views

Methodological test for choosing 'worse' models that make 'better' (more realistic) predictions?

I've run 4 models (simple LM, quadratic model, GLMM, and GLMM with quadratic) to predict tree age (age) from tree diameter (D) for each of 42 species (SPEC). The diameter data has all been log ...
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11 views

Analysis of pairwise differences in species composition between sampling dates

I have six timepoints (months) with 60 samples each. I want to assess the species composition changes over time. For single taxa i used glht() (multcomp) with the ...
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16 views

Choosing to adjust or not after Kruskal-Wallis rejection

I have a series of data (4 numerical variables) and 4 categorical variables (with multiple factors each). I need to test for differences between various subsets based on the categorical variables. ...
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7 views

main effect in 2-way ANOVA but not in Omnibus test

I ran a two-way repeated measures ANOVA, specifically a randomized block factorial ANOVA (design RBF-pq, with p=2 and q=3) in R. The factors were "mode" (with 2 levels) and "metric" (with 3 levels). ...
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33 views

Post hoc test for robust 3 way ANOVA

I am doing a 3x2x2 between subject study. To make thing simple, I name my variables as A, B and C here. Using the WRS 2 package in R, I have gotten results for the ...
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19 views

ANOVA for data does not fit the assumption of homogeneity of variance, which is better: ANOVA after ln-transformation or Welch's ANOVA

I have data, where many groups have different variance, so the data does not fit the assumption of homogeneity of variance. 1, First I ln-transformed all data, after all most of them had homogenous ...
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1answer
19 views

transitive property in statistical comparisons

I want to know if the exposure to a given dose of a toxic chemical alters the concentration of a given substance in blood in my animals. I make this super general, bear with me, because I think this ...
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9 views

Improve a tagging system based on future data learning

I need to improve a system that tags events as good/bad for model training set creation. The current system relies on 1-2 data points following the event (for the same customer) that could happen ...
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13 views

Strange results of post hoc test

I have nine different treatments involving Zinc application and each replication was replicated thrice. The data were not distributed normally even after data transformation. So I used Kruskal-Wallis ...
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26 views

Degree of freedom in post-hoc test

I have a crucial question (crucial for a statistic beginner as me...) I have run a 2x2 repeated meausure ANOVA between subjects where I had: Factor Between: Subject Category (14 musicians/14 ...
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1answer
63 views

Repeated Measures ANOVA and the Bonferroni post hoc test different results of significantly

I am doing an Repeated Measures ANOVA and the Bonferroni post hoc test for my data using R project. The ANOVA gives a significantly difference between the data but not the Bonferroni post hoc test. ...
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1answer
29 views

Should I use repeated meaure ANOVA?

I have 5 interaction techniques (eg., interaction 1 to 5) and I have recruited 15 participants to participate in my study. Each participant interacts with each of these 5 techniques only once. I will ...
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26 views

How to correct for multiple post-hoc tests in multi-factor ANOVA

Let's for the sake of this question assume we did an ANOVA with three factors A (3 levels), B (4 levels), and C (5 levels). We get significant main effects for A and B. In consequence we do three ...
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1answer
36 views

post hoc test for 3 way anova

I am doing ANOVA using three fixed independent factors of which one is sex (two levels 'male' and 'female'), temperature (three levels: 1,2,3) and quality (two levels: good and bad) and I want to see ...
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80 views

post hoc test for unequal sample size and variance

I have a data frame on which I am doing ANOVA using three fixed independent factors of which one is gender (two levels 'male' and 'female'), temperature (three levels: 1,2,3) and quality (two levels: ...
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49 views

two-way multiple comparisons in R

This is a subset of my dataset: ...
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17 views

ANOVA/post hoc w/ time (year) as independent variable

I'm using ANOVA to try to determine whether changes in 3rd grade reading scores in one school district are significant over a ten year period. Since each third grade cohort is comprised of new ...
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85 views

R, Pairwise comparison of random variable in mixed model

We measured temperatures of a pond repeatedly every day at each hour for a month at two different depths (i.e., top and bottom). We want to see if the temperatures at the top of the pond are ...
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29 views

Post hoc after a m x n Fisher-Freeman-Halton

I'm looking for a way to do a post-hoc analysis for a Fisher-Freeman-Halton analysis (Fisher's Exact for contingency tables larger than 2x2). For example I've found a significant difference on a 6 ...
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1answer
50 views

Between subject post-hoc tests in an ANOVA with repeated measurements

I run an ANOVA with two factors A & B and repeated measurements. Now, I'm mostly interested in the interaction effect of the two factors A*B and would like to do some post-hoc tests in the form of ...
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27 views

Post-hoc analysis of variable selection

I am using support vector machines & 10-fold cross-validation for a binary classification task. For feature selection, I use the t-test. After doing the classification, I'd like to do a post-hoc ...
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1answer
50 views

Repeated measures through time using mixed effects in R, plus post hoc tests

I have been trying to figure out how to do a fairly basic repeated measures analysis using linear mixed effects in R, and then analysing it using post-hoc tests. The problem is that I'm not sure ...
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1answer
55 views

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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1answer
52 views

Post-hoc test after a GLM with binary data

I have run various logistic regressions (GLM) from the binomial family and they have produced some very interesting results. I would now like to run post-hoc tests to find out which levels of the ...
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What to do when you have more than one column of dependent variable data?

I ran a 2x2x2 mixed Anova on my data I have only got a significant result for one factor and also a 3-way interaction. Trying to find out where the significance lies in the 3 way interaction at the ...
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57 views

Is there a consensus on adjusting alpha for multiple contrasts if the main effect is significant?

After talking to a couple of statisticians, reading some book sections, internet articles, and forums like this, I am still unclear about multiplicity adjustments of post hoc tests and contrasts. ...
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37 views

Explaining mixed-model interactions with ANOVA?

I have searched through the answers on this forum and I couldn't find any detailed explanation to my question about linear mixed models. Here is my setup: 4 groups with treatment X (one of which is ...
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1answer
31 views

Most appropriate test for my data?

I am strugling with my current science project on how to determine statistical significance among my tested groups. I have however a very basic understanding of statistics and would like to understand ...
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66 views

EMMEANS Pairwise Comparison OR Post Hoc Multiple Comparison?

I was running a 2-way Univariate ANOVA, and there are two tables in the results that compair the 3 levels of one of my IVs (Transformation_Model). Under Estimated Marginal Means, the table is titled ...
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1answer
281 views

Post-hoc testing in multcomp::glht for mixed-effects models (lme4) with interactions

I am new to CrossValidated, so if there is a better way for me to format or ask my question, please feel free to comment. I am performing post-hoc tests on a linear mixed-effects model in R (package ...
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41 views

Are the statistical words contrasts and post hoc synonymous?

I have implemented a linear mixed-effects model using lmer{} model in R and used glht to to ...
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1answer
55 views

Bonferroni method for multiple comparisons with 1-way layout

My statistics book describes the Bonferroni method of doing multiple comparisons with a one-way layout as essentially performing a t-test with each pair of interest with a significance level scaled ...
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2answers
129 views

Post hoc analysis for linear mixed model with nested effects

I'm having trouble in R with my Linear Mixed-Effects Model. I'm working with yeast in nectar. This is a part of my data just so you can see what is going on: For the condition sucrose, I have 4 ...
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40 views

Post-hoc test for prop.test with 3 samples

I am performing a prop.test() in R for 3 different groups (samples). The result is a p-value that tells me that the observed proportions differ between the groups. --> How can I now find out whether ...
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1answer
523 views

What is the difference between various Kruskal-Wallis post-hoc tests?

[There seem to be a lot of similar questions here, so please point me the right direction if this has already been answered, but I think it's reasonably differentiated.] There are many different ...
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1answer
34 views

Post Hoc Analysis in Mixed linear models

I tested whether different version-styles of a loading screen (hourglass vs. progress bar) in different progression patterns (linear, accelerate, decelerate, irregular, binary) affect time estimations ...
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26 views

Post-hoc test on 3 groups comparison

I have 3 groups each with 6 values. After performing acceptable levene test for Homogeneity of Variance, I performed Anova on my data. It was significant, and I started to perform post-hoc test. The ...
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1answer
245 views

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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112 views

Fisher's exact test for 3x5 contingency table in R with post-hoc? Consistently with using Fisher or Chi-squared?

I'm struggling with some (relatively simple) stats questions for some work I'm doing in R, and can't seem to find answers online... I have a factorial response variable of habitat type of a species ...
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1answer
108 views

How can I interpret a significant one-way repeated measures ANOVA with non-significant pairwise, bonferroni adjusted, comparisons?

I have a dataset with one factor consisting of four levels. I've run a one-way repeated measures ANOVA on the data, which came out significant. However, for the follow-up pairwise, bonferroni ...