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.

learn more… | top users | synonyms

0
votes
0answers
7 views

Does a Split File Datasat need a correction for multiple comparison?

I searched already for similiar problems but couldn't find an answer. I split the file in SPSS by a two-level between group variable (sequence) and then want to perform two ANOVAS on each of those ...
1
vote
3answers
63 views

Number of false positives after Bonferroni or FDR

Let's say I am doing 100,000 tests. If the tests are independent, at an alpha of 0.05, we would expect (on average) 5000 of these tests to be false positives. The Bonferroni method would penalize ...
1
vote
0answers
29 views

Binomial modelling, testing and Bonferroni

I am currently trying to validate an implementation that is supposed to randomly assign a certain number of tags to users who enter a platform. The variable of interest here for me is the sum of all ...
0
votes
0answers
15 views

multiple paired-sample t-test and Bonferroni Adjustment

I have 4 questionnaires: A,B,C,D. I also have another 4 items ($i_1,i_2.i_3,i_4$) that each measures some aspect of acceptability or feasibility of the questionnaires, which were answered following ...
0
votes
1answer
26 views

Bonferroni correction

I want to validate a questionnaire with three scales summing up to a total score. For for all tests I conducted, I tested the scales separately and additionally the total score (so 3+1 and that total ...
1
vote
0answers
14 views

Multiple testing correction for correlated test statistics

I have a matrix, the rows stand for the different diagnostic subgroups (6) and the columns stand for 4 different test statistics, making in total 24 values of test statistics. I should mention that ...
1
vote
0answers
14 views

Should I use t-test or ANOVA+post hoc (two different treatments and a control)

I have been working with ice algaes,and Im looking on their fattyacids. Here is a bit about the experimental design. I have one treatment area, cleared, where I have removed all snow. I have ...
1
vote
0answers
22 views

Multiple t tests with Bonferroni correction instead of Anova and posthoc?

I have a set of 6 experiments that were all performed at the same time. This consists of 3 genotypes (A, B, C) , each under two conditions (1 and 2) with a single measurement variable. I just want ...
1
vote
1answer
18 views

Question about adjusting for multiple testing

I have a question about adjusting pvalues to account for multiple testing, as I need to do this given a small sample size with a lot of tests. I have read that the most common and conservative method ...
0
votes
2answers
37 views

What if Bonferroni correction is too conservative for 3 correlations on same group of people?

I use Pearson's correlation to calculate association between Test A and performance on 3 subtests of test B. If I use Bonferroni correction for multiple comparison then alpha is 0.05/3 . we found ...
0
votes
1answer
18 views

post hoc tests in ANOVA

While I am doing post hoc test for one way ANOVA, I am getting significant results for LSD but the same variables does not have significant values for Bonferroni. Why is it so?
1
vote
0answers
33 views

a priori power analysis for ANOVA plus post hoc test

I would like to perform an a priori power analysis to calculate required sample size for data to be analyzed using one way ANOVA and Tukey HSD post hoc test. (I want to determine pair-wise which ...
0
votes
0answers
42 views

Different sample sizes, skewed data and unequal variances

I am a bit confused regarding best statistical test to use for my data. Here is the details: I did a study to compare two independent groups; 31 patients and 60 healthy controls. I have around 50 ...
1
vote
0answers
34 views

Multiple Hypothesis Testing with Categorical Variables and Alternatives

Suppose we have a variable $Y_i$ which is a binary categorical variable, and we have a variables: $X_{i,1}$, $X_{i,2}$, ....$X_{i,n}$ ($i=1,2,....N$ where $N$ is sample size, and $n$ is the number of ...
5
votes
3answers
220 views

Does Bonferroni apply to inference from parametric and non-parametric models?

I have run 6 independent-samples t-tests, and 4 Mann Whitney U tests. When applying Bonferroni correction, does it apply across all 10 tests? My hypotheses are that there will be 4 significant ...
0
votes
0answers
10 views

The use of MANOVA, ANOVA or t-tests for Likert-style data

I have two groups I would like to compare on a series of Likert-style mood dimensions (e.g. Very Sad - Slightly Sad - Neutral - Slightly Happy - Very Happy). The sample sizes are 19 and 63. The data ...
1
vote
1answer
43 views

How to say “the statistical significance of our result is stronger”?

I'm doing a Bonferroni correction, after which our result is still significant at the 10% level. Since my multiple outcomes are highly correlated, for which the Bonferroni is too conservative, I want ...
0
votes
0answers
36 views

Bonferroni correction in MANOVA

so if I've done a MANOVA and followed that up with Bonferroni correction and found that only 2 out of 7 variables are significant (whereas before there were a few more) does that mean that only these ...
1
vote
1answer
24 views

When is it ok to NOT control for multiple comparison?

My initial feeling was never. But I notice that whenever people write up a larger study (or a meta-study) they do not adjust the significance thresholds of the individual measurements to account for ...
20
votes
3answers
2k views

Why aren't multiple hypothesis corrections applied to all experiments since the dawn of time?

We know that we must apply Benjamini Hochberg-like corrections for multiple hypothesis testing to experiments based on a single data set, in order to control the false discovery rate, otherwise all ...
2
votes
2answers
82 views

Incremental adjustments of $\alpha$ for multiple hypothesis testing?

Given a nominal significance level of $\alpha$ for a single hypothesis test, I understand that if you do multiple tests, $i = 1$ to $m$, then according to Bonferroni's correction, the significance ...
0
votes
0answers
90 views

pairwise.t.test in R returning no value

I am a noob in R, and have been breaking my head for the past three hours over the pairwise.t.test in R. My data frame is structured as given below. My data frame has the age of flight of bees and the ...
0
votes
1answer
44 views

Assumptions on Multiple Comparison - Bonferroni and others

I was asked for an alternative procedure to multiple comparisons which does not require independence of the multiple tests being applied. IĀ“ve found some readings where BonferroniĀ“s correction is said ...
2
votes
1answer
57 views

Bonferroni Correction - When not to use it

In a discussion with another researcher, I was informed that it is not always necessary to perform a Bonferroni correction on exploratory research if a lot of testing is required (for example, if many ...
3
votes
2answers
45 views

Is Bonferroni correction used for multiple levels, multiple factors, or both?

Bonferroni correction can help us correct our alpha values in multiple statistical testing. One aspect that I am confused on: Is Bonferroni correction used when we have multiple levels (Does this ...
2
votes
1answer
58 views

Why is Bonferroni considered a conservative multiple comparison tool?

Bonferroni correction seems to be known as a "conservative" way to determine. Why is it called conservative? Is it because it assumes independence among all tests? Sort like Naive Bayes?
0
votes
0answers
16 views

Testing many proportions against each other…use logistic regression?

If I have an A/B/C/D/E/F/G test - i.e. I'm testing 5 test variations vs a control - what corrections do I need to make to be able to determine the best variation? To find winners vs the variation I ...
3
votes
0answers
60 views

Difference between one-way ANOVA and all pairwise comparisons with Bonferroni correction [duplicate]

If you have five groups and you wish to know if there is a significant difference between any of the group means, you would have to do 10 pairwise comparisons to test all possible pairs of means. You ...
1
vote
0answers
23 views

Appropriate Correction for 2 proportion test? --with example--

Below is an example of frequency data between observed and expected proportions. Can I simply run a 2-Proportion z test here? Or, would I be violating assumptions? If I were to run dozens of z tests (...
4
votes
1answer
66 views

Do I need a Bonferroni correction?

My study has me running several regression analyses to investigate my hypothesis, and I am struggling with the multiple comparisons problem. I have three separate metabolites as predictor variables, ...
3
votes
1answer
49 views

Least conservative multiple testing correction

This is a general question regarding multiple testing when making confidence intervals. Suppose I have an unknown vector $$\mu = (\mu_1, \dots, \mu_p).$$ My goal is to estimate this vector, and ...
0
votes
1answer
59 views

How come we have Bonferroni correction when we have ANOVA analysis?

ANOVA analysis can be used to determine the significance of multiple groups. Why do we need Bonferroni correction to re-compute the alpha values? ANOVA solves the problem of multiple testing by ...
0
votes
0answers
35 views

Fisher's exact test + Benjamini-Hochberg correction for 100s of tests gives 100s of significant terms; Question about representative subset?

We are doing Fisher's exact test for 1,000 items (genes) in a population of 20,000 (genes). After that we use Benjamini-Hochberg multiple-test correction. We get over 200 significant results (Gene ...
1
vote
1answer
31 views

Multiple Comparison correction for temporally correlated tests

My data consists of N~200 cells. For each cell I am seeing the response to a stimulus for the next 300ms, in bins of 5ms (150bins total). In order to get confidence bounds for each bin on whether a ...
0
votes
0answers
22 views

Bonferroni correction after hypergeometric test

I have a small doubt regarding a Bonferroni after running an hypergeometric test on genomic data. Let say I have a population of 379876 output data(integer numebers), and this population is clustered ...
0
votes
0answers
28 views

When shall I use multiple comparison adjustment if I perform a series of Chi-square?

I am presenting some descriptive statistics about % of access to a service in different regions (12) of a country in my bar graph over two time period points. As the results are based on 12 2X2 tables ...
0
votes
1answer
48 views

Some new questions re the Bonferroni correction

When the Bonferroni correction is used, what is the actual test that is conducted? For example, is it the t-test? If you know the formula, that would be great. SPSS gives P values for each pairwise ...
0
votes
0answers
60 views

Does testing multiple interaction terms result in multiple testing problems?

I have been testing interaction terms in a regression model using likelihood ratio tests, and dropping any terms from the model if insignificant. I do not want to assume a priori that there are no ...
3
votes
1answer
53 views

What is the correct terminology for one/two-tailed p-values and how do I apply the Holm-Bonferroni correction?

I have been struggling to reconcile my (very basic) understanding of P-values with the approach of one of my colleagues and it appears to come down to interpretation of p-value terminology. This is ...
0
votes
0answers
45 views

Interpreting Results from Multiple Comparisons and Joint Significance test

I am conducting a study to test whether the manufacturing quality of a machine has an effect on its failure time. I am using a hazard model with a dummy variable to identify machines manufactured with ...
0
votes
0answers
9 views

When performing a factorial design two-way ANOVA, why do we conduct a mean seperation test on the data after finding no interaction?

I am a college student who must perform a factorial two-way ANOVA on a specific experiment. My professor told me that I would have to test for interaction among the data points first. If I find no ...
1
vote
0answers
19 views

Multiple Comparisons Corrections within Subgroups

I've got a set of data points with "scores" that belong to a series of subgroups (not necessarily disjoint). That is, I may have a point that belongs to groups A, B, and D, and then another point that ...
0
votes
0answers
76 views

Interpretation of Bonferroni confidence interval

When simultaneous confidence intervals for $B_0$ and $B_1$ are built by the Bonferroni method, with a confidence coefficient of $\gamma=0.90$, we can interpret that in 10% of the times $B_0$ ...
0
votes
0answers
13 views

how to (not) plot all pvals if many contrasts are done

I have run an ANOVA and then a Bonferroni test, using 8 groups. Therefore, the significant pvalues are many and showing them in a plot is messy. How would you recommend to approach this ...
0
votes
1answer
43 views

Mann-Whitney significance and multiple hypothesis testing significance

I am performing various comparisons using the Mann-Whitney U test. Because I'm comparing various groups simultaneously, I would am also correcting the p-values for multiple hypothesis testing using ...
2
votes
1answer
52 views

Why do I need a Bonferroni correction if we are evaluating our primary outcome?

We have completed a study comparing control with vitamin D supplement and with bone building drug. The primary outcome is change in bone mineral density. My statistician states that because we are ...
1
vote
0answers
33 views

Hypothesis testing with finite interval as null hypothesis

There exist two-tailed tests ($H_0: \mu = c$) and one-tailed tests ($H_0: \mu \leq c$ and $H_0: \mu \geq c$). I am interested in the case of the null hypothesis being an interval, that is $H^{ab}_0: \...
0
votes
0answers
417 views

Finding the Significant Differences (with p-values) in a 4x2 Chi-Square Table Using SPSS

In short, I would like to learn how to discover where the significant differences lie within a 4x2 Chi-Square table and report the significant findings with a p-value, preferably using SPSS. Setup: ...
4
votes
0answers
96 views

Cherry picking and low p-values

Let's say I run a lot of univariate OLS regression models, say 200,000, with 50 data points, then cherry pick the best one (highest r-square). If my $p$-value for this model is way less than 1/200,000,...
0
votes
0answers
51 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 ...