All Questions
Tagged with bonferroni t-test
31 questions
10
votes
4
answers
21k
views
Many p-values are equal to 1 after Bonferroni correction; is it normal?
I have behavioral data for 10 animals that I studied at two different times of day, AM and PM. I am looking to see if there is a significant difference in 8 different behaviors at AM vs. PM. I have ...
- 101
8
votes
2
answers
22k
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 ...
- 251
6
votes
1
answer
100
views
Which family-wise correction is needed for one-sided t-tests in a randomized controlled trial with several independent measures across groups?
I conducted a randomized controlled experiment with groups $A$, $B$, $C$, and $D$, each containing around $40$ human participants who saw one of four variants of a website. Group $A$ saw a baseline, ...
- 161
6
votes
3
answers
2k
views
How to correctly do a nested test (t-test, rank-sum, etc)
Let's say there are two groups of participants. Each group is randomly split into control subgroup A and task subgroup B. For each of the 4 cases some random variable $x$ is measured, whose mean is ...
- 2,131
5
votes
3
answers
857
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 ...
- 183
4
votes
1
answer
300
views
What is the basis for adjusting critical values in multiple t-tests?
Let's say I have three samples: control, A, and B. (I am assuming basic things about sampling like no bias, no confounding factors, and independence in selecting samples.)
I want to see if there is a ...
- 41
2
votes
2
answers
74
views
In a muddle with Paired Samples t-tests on pre vs during vs post
I have used paired samples t-tests to compare 3x time-point measurements, A/ B/ C.
A and B t(102)=4.988 p=.000
A and C t(102)=4.939 p=.000
B and C t(102)=.346 p=.730
A, B, and C were all significant ...
2
votes
1
answer
277
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 ...
- 21
2
votes
1
answer
250
views
Can we use the binomial distribution instead of Bonferroni correction for large number of independent significant tests?
Supposing we are doing e.g 1000 one-sample t-tests with the null hypothesis that all population means are 0, with significance level 0.01. One common method for dealing with the number of tests is to ...
- 31
2
votes
0
answers
927
views
Run multiple T-test and correct for multiple comparisons [closed]
I have tried to look for a quick way to solve this questions but I have found no complete solution so I decided to post the question.
I have a dataset about the rate of heat gain on four types of ...
2
votes
1
answer
379
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 ...
- 21
1
vote
2
answers
94
views
Do I need to use Bonferroni correction?
I have a dataset containing the selling price of mineral stones that were sold in five different countries (namely Germany, France, Italy, Belgium and Spain). I am running multiple t-tests check if ...
- 71
1
vote
2
answers
2k
views
Multiple t-test and Bonferroni correction
I have 11 subjects and also have the percentage value for the accuracy of a method I developed to predict future actions for each individual. I want to use a right tail one-sample t-test to find out ...
- 31
1
vote
1
answer
220
views
Bonferroni (or BH) correction for multiple t-test?
I'm studying the kinematics differences between males and females examined at two different specific walking speeds (slow/fast). Specifically, I'm exploring:
a) slow speed vs high speed (dependent t-...
- 23
1
vote
2
answers
59
views
Hochberg/Bonferonni correction for multiple one-sample t test
I am trying to conduct a content validity analysis where I want to test if a certain item (e.g. a question) can be related to a certain construct (e.g. depression). I've let people fill in a ...
- 329
1
vote
0
answers
21
views
posthoc paired t test
Is there a website with a calculator to input 2 sets of data to perform the post paired t test adjusted with the Bonferroni correction? Or is anyone available to hire?
- 11
1
vote
0
answers
76
views
Need to run Bonferroni correction if only doing 1 paired-samples t-test?
Say I have a significant interaction for a 2x3 within-subjects ANOVA. If I have a theoretical justification for only running a single paired samples t-test to look at simple main effects (even when ...
- 23
1
vote
0
answers
10
views
Should multiple adjustedment correction be applied here?
I have a question. I'm analysing an article for an assignement.
In this study there are two groups (normal d-dimer vs elevated d-dimer). The study compaires the mean of the groups for multiple ...
- 11
1
vote
0
answers
1k
views
Bonferroni correction in independent samples t-test?
I have three IVs with two levels/groups. My primary hypothesis is that there will be group differences for all IVs in total score. However, total score is comprised of scores on 7 subscales. Total ...
- 21
1
vote
0
answers
185
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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 ...
- 11
1
vote
0
answers
306
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 ...
0
votes
1
answer
8k
views
Multiple paired t-tests. Bonferroni number of comparisons?
I have done 9 paired t-tests, to see if there are significant changes in pre and post measurements of three variables (FFMQ-SF, GSE, WEMWBS), across three groups (Engagement level: minimum, medium, ...
- 25
0
votes
2
answers
303
views
Unusual Bonferroni correction
Assume my hypothesis is: "Light supports the performance of students." The experimental setting consists of two room conditions that students are randomized to. The "light" group takes a test in a ...
- 3
0
votes
1
answer
2k
views
Significant main effect but no interaction which post hoc test to do?
I have an experiment looking at the effect of rearing condition on development of the number of neural networks (ensembles) in mice. I therefore have two factors (Age 3, 5, 7 dpf) and Rearing ...
0
votes
1
answer
147
views
Correcting for multiple tests over time
I am measuring degradation of RNA over time with a control and a treatment. I have % RNA remaining (relative to time 0 for control and treatment) and 5 time points. I would like to test if the % ...
- 1
0
votes
1
answer
427
views
Is Bonferroni correction needed for independent samples T-test on grouped data?
I have conducted three tests (math, Biology, Chinese) on 4 groups of students who are coming from Hong Kong, Pakistan, Philippines, and Singapore respectively.
I have the following dataset with the ...
- 13
0
votes
0
answers
62
views
log2 p-value of 1 after Holm-Bonferroni correction
I obtained rawp by performing Student's t-test function on dat.filtered and then I performed correction using Holm and Holm-Bonferroni methods. I have a huge increase in log2 adjusted p-value of 1.0. ...
- 11
0
votes
0
answers
34
views
Multiple comparison when testing one planned hypothesis
I am running one logit model containing an interaction:
logit dv year contract_type yearXcontract+Z
where contract_type and year are dummies with 4 levels.
After ...
0
votes
0
answers
35
views
Do I need to "correct"?
I am testing whether a certain learning intervention affects student achievement. I have two groups of students (control and experimental) with 16 students each. I have their pre-test and post-test ...
0
votes
0
answers
21
views
Bonferroni Correction When Using Dates as Data Points [duplicate]
I have a test and control group in which I tested the impact of a sale on baseline revenue across a 3 week period (test received sale, control did not).
...
- 249
0
votes
1
answer
173
views
Bonferroni correction when comparing sub-group with rest of the group
I am working with 4 machines that test products and record a value during each test. I have ~ 1000 records from each, and some recorded values look like: -0.67, 0.3, 5.7, 2.3, -0.78, 5.2, 5.8, 9, 2.1,...