# multiple comparisions

1. ### Reporting corrected correlations

Hi All, I need to report a large set of correlations whose p values I have already corrected for multiple comparisons using R. I assume that the correlation coefficient will remain the same, as nothing in the r formula has anything to do with how the p value is calculated. 1) Is that correct...
2. ### False discovery and multiple test

I'm reading about the familywise error rate here and trying to put it into perspective. According to this, we calculate FWER = 1 - (1 - alpha)^n. In their example n=10, and with alpha .05, they say this gives 40.1% chance of a type 1 error. Is this practically saying that if i run a study and...
3. ### Why three-way ANOVA doesn't match with multiple comparisons?

Hi, I'm running a three-way ANOVA on a multifactorial dataset and it says all three (Device, HRT, Dose) variable has a significant influence on the data. However, when I run multiple comparisons, groupings and significance appear only based on one of the variables (Dose). Why is that and which...
4. ### Bayesian multiple comparison correction?

Hi everyone, I am new to Bayesian statistics and am interested in the correlation of 4 "target" variables with 52 other variables. Currently I am running several separate Bayesian Spearman rank correlations. Many of the variables are highly correlated (up to .68). Finally, I would like to...
5. ### compare 4 groups on several categorical characteristics

Hi! For my student research assistant job I have collected many pictures of dogs, and these dogs can be divided into four groups (young vs. old and breed 1 vs. breed 2). Before we are going to show the pictures to participants to compare these groups, we first want to make sure that some...
6. ### t-test or ANOVA? urgent

Hi, I am looking for advice about which stat test to use in my data analysis for our psychology class. We collected data on reasoning tests scores. I have two groups of participants 1) non-bilingual 2) bilingual and dependent variable in the form of reasoning scores in 1) spatial reasoning...
7. ### Multiple ANCOVAs: Post hoc Bonferroni, FDR, or can I use MANCOVA?

Hi, I am comparing a protein level in multiple (40 to 4000 depending on the analysis) brain areas across three diagnostic groups, with a couple of covariates. I am using ANCOVA to compare the three groups. What is the best way to account for multiple comparisons? Where I am conducting large...
8. ### Generalized linear mixed model: Type III significant but multiple comparisons not significant

Hi guys I am running a glmm model for my data, the Type III tests of fixed effects is showing that there is a significant effect of treatment but when i run the multiple comparisons, non of the treatment levels are significant. What causes this confusion? Is my model not right maybe? Regards...
9. ### Correct p-values multiple testing mixed models

I am trying to figure out how to correct for multiple testing when having several mixed models. I am using R, nlme package to make the models. I have run 14 mixed models for 14 pre-defined continuous output variables. 1 model is the primary outcome and 13 models are the secondary outcomes. It...
10. ### Multiple Comparisons across events with discrete probabilities?

Been stuck on this problem for a few days. I have calculated many distributions that are all non-parametric, but appear to have trended to be approximately normal. I think a helpful way to visualize what I've done is a matrix with 24 columns and 16 rows. Each cell has one of these distributions...
11. ### Benchmarking and Statistical Difference

Hey everyone, I have a few issues and would really appreciate your help :) Thank you very much ! So here it goes : I have two levels ( A and B ), in different fiscal years ( 2007 - 2011 ) and approximately 15 variables. I would like to calculate the mean, variance, kurtosis and...
12. ### Kruskal Wallis - Specific multiple comparisons

Dear all, I'm new to the board, but I hope you're able to help me. I'm using SPSS for my statistics. My outcome is scale variables (eg height, weight, etc.) - a total of 20 different variables. I have 8 different groups where I need to test 8 relevant combinations per variable. My first...
13. ### Controlling for Type 1 Errors: Post-hoc testing on more than 1 ANOVA

I have conducted several repeated-measures ANOVA's with post-hoc testing via Tukey's HSD whenever the omnibus F-test was significant. I'm having some confusion about controlling for type 1 errors when presenting these post hoc tests. Q1: It's my understanding that Tukey's HSD will control the...
14. ### perMANOVA using Adonis in Program R (DF and Multiple Comparisions)

Hello there, I’ve been having some concerns with the degrees of freedom R has been giving me from PERMANOVA (adonis), and I was hoping someone could shed some light on this. I have been looking over my R books and manuals, general statistics books for calculating DF, and surfed the stats...