Bonferroni refers to a method of adjustment for multiple comparisons in which the p value is divided by the number of tests. It is more conservative than many other such methods.

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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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45 views

Multiple testing adjustment in linear models

I have troubles with multiple testing correction (For example, bonferroni adjustment. I'm aware that it's not most correct one). ...
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29 views

Dependence, independence, multiple testing, and alpha error correction

although I have studied psychology and feel I should know a lot more about issues such as this one, I have a quite basic question (or maybe not so basic question, considering all the fuss about this) ...
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21 views

Bonferroni post hoc test in R for repeated measure ANOVA with mixed within and between subjects design

I need to perform a Bonferroni post hoc test in R on a table with three within subjects factors (Emotion, having 5 levels, Material, having 4 levels, Shoes, having 2 levels) and one between subject ...
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22 views

Bonferroni correction for multiple testing and overlapping groups

I have allele frequency observations from a large geographic region that can be logically subdivided into smaller areas in a number of different and meaningful ways. If I were to test these ...
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62 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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23 views

What to do after a significant Exact test?

I have significant Fisher exact tests for a 2x3 and 6x3 contingency table. All I can get from it is that the observation regarding columns and rows are not random. But I don't know which combination ...
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27 views

Does the bonferonni correction change the outcome of the p-value or is it just changin what you accept as significant?

For some reason I can't seem to integrate the bonferonni corrected p adjustment into my multiple comparisons t test in r so I need to do each of my 3 tests individually. What I wondered was do I need ...
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43 views

Bonferroni Adjustment and Assumptions?

I'd just like to get clarification on something. When you perform a bonferroni adjustment (dividing the alpha level by the amount of tests you want to do, if say you're doing multiple ANOVAs) do you ...
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28 views

Bonferroni correction of bootstrap generated p values

I have run a multiple regression analysis with 900 independent variables and bootstrapped this analysis 1000 times, with replacement, to generate bootstrap p values. When I looked at the results, I ...
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30 views

Do I need to use a Bonferroni adjustment?

I am using three different ANOVAs to determine significance across two treatment levels. Because we only have two species I chose to run the same set of analyses for each of the species instead of ...
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1answer
83 views

Bonferroni Correction p value in SPSS [duplicate]

I have run an analysis on data using SPSS. I have a repeated measures design with 7 conditions. I chose to do pairwise comparisons to see where the effects lie and used the Bonferroni correction. If ...
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30 views

Bonferroni Corrections for multiple control groups

We recently ran a marketing test at work where we are looking at the amount of customers that make a transaction at the store if we do not email them, Email them, email them AND send them a physical ...
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49 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

Standard multiple regression and multiple dependent variables. and bonferroni correction?

I have a question regarding running multiple regression equations with multiple dependent variables. Three independent variables and 3 dependent variables. A colleague advised me to conduct three ...
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1answer
106 views

Confidence intervals from the Holm-Bonferroni test?

I'm a newcomer in the problem of multiple comparisons. I wonder how to calculate confidence intervals for Holm-Bonferroni method? I know that for Bonferroni method we can just change the confidence ...
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34 views

Bonferroni adjustment according to which families?

We have 17 subjects in a crossover design of three groups: Challenge agent (CA) CA+ compound of interest (CI) CI - Our data proves this has no physiological effect, and is thus not used in ...
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1answer
49 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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24 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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79 views

Significant Friedman's test vs. non-significant multiple comparisons

I am currently running a randomized, placebo-controlled, cross-over design for a new type of intervention. This intervention is compared to a placebo and another more conventional type of treatment. ...
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41 views

Multiple t-tests and Bonferroni

I have two independent groups (healthy weight and overweight) and want to compare three different variables between the two groups (BP, cholesterol, body fat). I know I need to run three separate ...
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105 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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26 views

Which means difference test to use?

Currently, my data is count data and I am analyzing it in Proc Glimmix in SAS. My data focuses on how many times birds from two treatments performed stand, sit, forage, ect.... So it basically looks ...
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2answers
83 views

Multiple test correction for categorical variables with many levels

I am creating a binary logistic regression model with the inputs as a single categorical variable with 100 levels. My goal is to find which level of the categorical variable is most likely to result ...
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394 views

Bonferroni correction on multiple Kruskal-Wallis tests

My data consists of 3 groups, and 6 variables. The data are not normal so I want to use non-parametric tests to uncover significance. The first thing I wanted to get your opinion on is, is it ...
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23 views

Bonferroni family of confidence intervals for fitted values from loess method

I did loess nonparametric regression using one predictor and I wanted to build confidence band around my fitted values. I saw the some posts(links below) for this topic and found that an approximation ...
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230 views

Report in ANCOVA: descriptive means or estimated marginal means?

I have conducted an analysis of covariance, ANCOVA, followed by Bonferroni post-hoc tests, on SPSS. I want to report the differences between my groups in text (APA style) and in a corresponding bar ...
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How is plot of p-values distribution related to calculation of the false discovery rate?

I'm running t-tests for all combinations of pairwise comparisons of average length of stay for patients among 30 hospitals. My first approach was to use a Bonferroni corrected significance level of ...
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129 views

p-value correction for multiple t-tests?

My dataset consists of $n$ genes, each of them described by a vector of expression values, $5$ for "healthy" individuals, and $5$ for "unhealthy" individuals. I am going to run $n$ t-tests (one for ...
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88 views

multiple pair wise nonparametric comparisons

is it possible to perform multiple pair wise nonparametric comparisons (generally using a Mann–Whitney test) and adjust the significance level used for the decision criteria using a Bonferroni-type ...
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205 views

Post-hoc with Bonferroni a correction after ANOVA with repeated measure in SPSS

does somebody know where I can find the t value of post-hoc tests with Bonferroni correction when using SPSS.From what I get so far, I only see p values. Should I add a command in the script? Thank ...
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32 views

Statistical test for Comparing 6 classifiers over 5 datasets

I did the Friedman test to compare 6 classifiers which are tested over 5 datasets. The null hypothesis was rejected so I proceed with the post-hoc Bonferroni. The X classifier is always first on all ...
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314 views

How to best approach ANOVA with multiple response variables that might be correlated and Bonferroni Correction

I need some help verifying a simple analysis. I have completed a simple two factor experiment of more or less equal sample sizes. Let's assume for the case of this question that the sample sizes are ...
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11 views

Appropriate correction for tests for determining best of family

I have a sample of $N$ instances of a problem (assumed to be independent samples of an infinite population of instances). To each of these instances I apply $M$ methods, and record how quickly they ...
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315 views

What's wrong with Bonferroni adjustments

I had read an article has this title "What's wrong with Bonferroni adjustments?" for Thomas V Perneger He summarized saying that Bonferroni adjustment have, at best, limited applications in ...
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Is Bonferroni Correction Appropriate for this Analysis?

Suppose I have performed a study wherein I compare a novel intervention (N) against the standard intervention (S). Participants are assigned to N or S randomly, and the study is performed. There are ...
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30 views

Do I need to do p-value correction after Kendall correlations?

I'm a neuroscientist and I've done some statistics before, but I'm fairly new to corrections of the p-value (like Bonferroni). I've got 2 groups of patients. For each group, I look into 3 areas of ...
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1answer
123 views

How to describe three groups where the means of two groups are significantly different, but neither of the two groups differ from a third group?

I am comparing 3 means from normal distributions using student's test: $\mu{_1}, \mu{_2}, \mu{_3}$ Results are: $\mu{_1} = \mu{_2}, \mu{_2} = \mu{_3}, \mu{_1} \ne \mu{_3} $ If I want to group my ...
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118 views

Extent of multiple testing correction

A bit of a strange question. In my fourth year biostatistics class today, we were discussing when and when not to use multiple testing correction, and the professor made an offhand comment. He asked ...
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26 views

Follow up comparisons for a repeated measures ANOVA while ignoring some factors

So I have a big data frame with my dependent variable stored in RT and my subject number stored in s. I'm interested in doing within-subject ANOVAs on the means of each subject score per unique ...
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1answer
156 views

Appropriate non-parametric post-hoc test for baseline comparisons?

I want to evaluate several "classifiers" (machine-learning algorithms) with paired samples. I do not want to compare each algorithms' performance to every other (n x m comparison) but only compare the ...
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4answers
752 views

About the Bonferroni correction

I have 50 variables in my dataset. I have correlated each variable against each variable, thus I have $49·50/2 = 1225$ unique correlations when no variable is tested against itself. Now, suppose I ...
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38 views

Multiple comparisons, multidimensional data, several groups

Could you please help me with such a problem: Let's assume I have multidimensional data that consists of 30 samples and 10 variables. This is a 30x10 matrix. I have three groups of equal size (10 ...
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2answers
162 views

Why is the Bonferroni correction properly used with planned, and not post hoc, contrasts?

The Wikipedia article on Post hoc analysis says "Bonferroni correction (This is properly used with planned, not post hoc, contrasts.)" but does not explain why the Bonferroni correction is properly ...
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1answer
65 views

What is the intuition for dependence assumption in Benjamini and Hochberg (1995)?

For dealing with multiple testing, Benjamini and Hochberg (1995) assume that the tests are independent. Benjamini and Yekutieli (2001) show that (1) the 1995 result also holds under (I think) weaker ...
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1answer
62 views

Using a binomial approach to calculate significance of multiple significance tests

I have 10 data sets with normal distributions and carrying out significance tests on each one. With this many data sets, there is a good chance that some will be significant by chance. I am going to ...
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2answers
2k views

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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1answer
732 views

When to correct p-values in multiple comparisons?

I'm afraid that related questions didn't answer mine. We evaluate the performances of >2 classifiers (machine learning). Our Null hypothesis is that performances do not differ. We perform parametric ...
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1answer
313 views

When should I use FDR or Bonferroni in multiple comparisons?

I have the following situations : (1) Very large number of variables - say 100 variables and 200 samples (observations). Although level of each variable is just 2 or 3 or 4 max. I am doing linear ...
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2answers
37 views

What are correlations among between test statistics in multiple comparison procedures

In the book Multiple Comparisons Using R Bretz et al write that their R package multcomp improves power above other multiple comparison procedures by "accounting for the structural correlations ...