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

learn more… | top users | synonyms

0
votes
1answer
9 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 ...
0
votes
0answers
4 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 ...
0
votes
0answers
11 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 ...
0
votes
0answers
18 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 ...
1
vote
1answer
53 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. ...
0
votes
1answer
26 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 ...
0
votes
0answers
22 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 ...
0
votes
1answer
20 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 ...
0
votes
0answers
32 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: ...
0
votes
1answer
43 views

two-way multiple comparisons in R

This is a subset of my dataset: ...
0
votes
0answers
11 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 ...
1
vote
1answer
59 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 ...
1
vote
0answers
19 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 ...
1
vote
1answer
33 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 ...
0
votes
0answers
25 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 ...
0
votes
1answer
41 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 ...
2
votes
1answer
35 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 ...
0
votes
1answer
28 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 ...
1
vote
0answers
20 views

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 ...
2
votes
0answers
37 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. ...
0
votes
0answers
28 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 ...
1
vote
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 ...
0
votes
0answers
43 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 ...
0
votes
1answer
128 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 ...
0
votes
0answers
32 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 ...
1
vote
1answer
45 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 ...
0
votes
2answers
92 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 ...
0
votes
0answers
29 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 ...
3
votes
1answer
335 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 ...
0
votes
1answer
30 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 ...
0
votes
0answers
22 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 ...
5
votes
1answer
158 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 ...
0
votes
0answers
93 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 ...
0
votes
1answer
83 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 ...
0
votes
1answer
70 views

nlme fixed effects analysis recommendations

I have only a very basic background in statistics, and I have a possibly simple question, but I'm having a bit of trouble with my model. I suppose this is also an R question, but also statistical! ...
4
votes
1answer
470 views

Post-hoc test for chi-square goodness-of-fit test

I'm conducting a chi-square goodness-of-fit (GOF) test with three categories and specifically want to test the null that the population proportions in each category are equal (i.e., the proportion is ...
0
votes
1answer
55 views

Can assumptions of a statistical test be tested post-hoc?

Suppose I ran 100 1-factor ANOVAs. I find some significant results. Now, since ANOVA has some assumptions, I should test if they hold. So, can I run for example Levene's tests (to check equity of ...
0
votes
1answer
126 views

Tukey's test on two way ANOVA

So I have done a two way ANOVA, and would like to do a post-hoc Tukey's HSD test. What should I use for the $k$, SE, degrees of freedom and what is my $q$ and HSD? The exp is done in 4 places with ...
0
votes
0answers
50 views

Post-hoc analysis

Ok so maybe stupid question but I need to know, if im doing a post-hoc, and my experiment has two sources of variation, and one of them is significant and one is not. Do I only look at the means of ...
0
votes
1answer
95 views

Post-tests to consider in mixed models

I have a mixed model of the form y~condition + Replicate + Error(Replicate) but at the moment, and am running into difficulties in performing a post-hoc test. I ...
2
votes
1answer
107 views

Multiple comparisons with many groups

I would like to determine if using multiple comparisons test would be appropriate for my data. I used the Kruskal-Wallis test to determine if there were differences in mean inhibition among $17$ ...
1
vote
1answer
282 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 ...
2
votes
1answer
582 views

How to follow up a factorial MANOVA with discriminant analysis?

This is a follow-up to to my previous question: How can MANOVA report a significant difference when none of the univariate ANOVAs reaches significance? I have two IVs with each having three levels ...
2
votes
0answers
57 views

ANOVA P-value adjustments for semi-continuous data

In tests such as the Bonferroni post-hoc p-value adjustment test, convention is to correct the data with a constant, equivalent to the length (number) of pairwise comparisons that are being performed. ...
7
votes
2answers
325 views

What is the problem with post-hoc testing?

My statistic professor says so, all the books that I look at state it: post-hoc-testing is unscientific. You must derive a hypothesis from theory first, and then collect data and analyse it. But I ...
2
votes
2answers
263 views

Minimum sample size for 1 way ANOVA?

I have tested a group of participants over various time points and I want to investigate whether mean score on each subsequent time point is significantly different to the mean score at baseline (eg. ...
0
votes
0answers
26 views

post hoc nested

Hy, need to do post hoc test for nested factor in SAS. I have two factors, A and B with B nested within A and I want to perform post hoc test in GLM in SAS. Is it possible? Stevan
0
votes
0answers
36 views

What type of post hoc test does a LME use by default?

I need to know what type of post hoc test a LME model is using in R, by default? Is it Tukey? And is the alpha modified?
2
votes
0answers
229 views

Converting Chi Square Adjusted Residuals to p values

I am running a chi squared analysis in SPSS on a 5 x 2 contingency table. The overall chi square p value was < 0.0005, so I ran post hoc tests (adjusted standardized residuals on the individual ...
0
votes
0answers
42 views

What is the relationship between degrees of freedom and number of comparisons in Nemenyi's post hoc test?

I have some data consisting of non-normally distributed samples drawn from one of several different groups. A Kruskal-Wallis 1-way ANOVA rejects the null hypothesis that the medians of the groups are ...