"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

4
votes
1answer
44 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
46 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
24 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
21 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
41 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
26 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
32 views

Bonferonni 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
102 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
36 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. ...
6
votes
1answer
262 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
41 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
9 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
20 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
76 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
27 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 ...
2
votes
1answer
23 views

Can I justify using a one-tailed test in for this interaction effect?

I have an experimental setup with 2 factors, site and disturbance treatment. I have reason to suspect that plots at site A will be more affected by treatment than plots at site B. My response ...
0
votes
0answers
45 views

When an effect size has to be considered sufficiently large?

I submitted a paper in which I analyzed the data by a mixed design ANOVA. I reported generalized eta squared as effect size. After significant interactions, I conducted planned comparisons. A reviewer ...
0
votes
1answer
77 views

Post Hoc test after lme [closed]

I am trying to run a Post Hoc test (glht) after a linear mixed model (lme) in R. I was ...
3
votes
1answer
50 views

Post-hoc after GLM: What does it exactly say?

Background: I have been asked to model the change of weight of a few animals undergoing experimentation via a simple GLM (General Linear Model). The data looks something like this. Note that all data ...
0
votes
0answers
40 views

How does one do a Post-hoc test for a Poisson glm in R?

My data consists of the following categories: Site - 3 sites - Boulder, Rubble and Cul-de-Sac Season - 4 types - warm1, warm2, cold1 and cold2 Behaviour - 6 behaviours scored - Basking, ...
0
votes
0answers
42 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 ...
0
votes
3answers
73 views

Testing and reporting interactions in multiple regression

I have a model with two between-participants predictors -- one continuous (a), and one categorical with two levels (b) -- and ...
0
votes
0answers
37 views

Can one make a Tukey post-hoc test for multiple regression in R and how?

I saw that the Tukey post-hoc test is usually done after performing an ANOVA. However, is it possible to carry it out in the case of multiple regression with the following model: ...
3
votes
0answers
41 views

Post-hoc power analysis of complex sample survey data

I am working with a complex sample survey data using Stata to determine the predictors of a given dependent variable. As part of my analysis result I want to report the post-hoc power for each ...
0
votes
0answers
24 views

Pairwise comparison of slopes from multivariate regression model in R

I am investigating size changes over time. I have five size variables in a multivariate linear model against year. I used the Anova() function in the car package to test whether the slopes are equal ...
0
votes
0answers
9 views

Follow up 2-way ANOVAs

I have a three-way significant interaction in a mixed-ANOVA, with two repeated-measures factors and one between-subjects factor. I would now like to follow it up with a repeated-measure ANOVA for each ...
0
votes
0answers
36 views

Post hoc for GLM that looks at interactions (in R)

I’d like some help with analysing some count data. I am very new to R (and statistical analysis for that matter!) and have done my best to work it out on my own … but seemed to have got stuck! I am ...
0
votes
0answers
31 views

How to use controls as a reference in GLM?

I'm running glms in R on two datasets, both with three discrete explanatory variables and one continuous dependent variable. My question is about the use of controls - I want to use my controls as a ...
0
votes
0answers
56 views

mixed design and simple main effect analysis in SPSS

Hope someone can help me. I have a within subject variable (Question, with 11 conditions) and a between subject variable (stimulation, with 3 conditions). I did an ANOVA and I obtained a main effect ...
0
votes
1answer
118 views

Which post-hoc is more valid for multiple comparison of an unbalanced lmer-model: lsm or mcp?

After doing a model comparison with my mixed lmer model, I have a model with three main effects, no interaction, say ...
0
votes
0answers
53 views

How do I report the result of an mcp-Tukey-test, i.e. how do I report it's z value?

After doing a model comparison with my mixed lmer model, I have a model with two main effects, no interaction, say signal ~ factor A + factor B + (1|subj). Factor ...
0
votes
0answers
49 views

GEE and post hoc comparisons

I am trying to analyze a dataset using the GEE. This is what I have so far ...
0
votes
0answers
35 views

Looking for a better post-hoc analysis

I'm a PhD student in Neuroscience, with a master degree in Psychology and I use R for my statistical analyses. As you know, in NHST usually post-hoc analysis in continuous data are essentially ...
0
votes
1answer
208 views

F stats for post hoc test of a linear mixed effects model

I have an unbalanced linear mixed effects model with three fixed factors of various levels and one random factor for my repeated measures data (for details see here). Thanks to your help I managed to ...
1
vote
2answers
55 views

Post hoc Scheffé test

My 1-way ANOVA test is not significant. Is it possible that a Scheffé test as a post hoc test be significant? If not, please say why not.
0
votes
1answer
76 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 ...
0
votes
1answer
36 views

Refitting with different contrasts vs. pairwise comparisons

Say, I fit a linear or generalised linear model in R with dummy coding (contr.treatment for ...
0
votes
1answer
40 views

Effect sizes for post-hoc paired comparisons in one-way ANOVA

Is there any alternative (like Cohen's d in t-test) to report about effect sizes for post-hoc paired comparisons in a one-way ANOVA (3 factor levels, correlated samples)?. Many thanks!!
1
vote
1answer
99 views

Mixed ANOVA post hoc analysis (and multiple comparisons)

I have a set of 12 subjects: 6 administred with drug A and 6 with drug B. For each subject two time-points have been collected (before and after drug treatment) for each analyte (over 6000). I had a ...
0
votes
2answers
158 views

Post-hoc tests for 2x2 ANOVAs (Type II & III) with interactions in R

I am trying to analyze data from an experiment using R and ran across a problem regarding the use of post-hoc tests with Type II & III ANOVAs. I only know of R functions that perform post-hoc ...
3
votes
1answer
54 views

GLM post hoc with non-parametric tests?

I have a question regarding the appropriate use of comparisons for independent samples (3 factor levels). Overall sample size is N=546, subsamples: 218 or 228 or 100), convenience sampling, ...
1
vote
1answer
235 views

Standard error bars overlap but significance - estimated marginal means versus observed means

I'm running a Mixed effects model ANOVA with two fixed factors (condition, repetition) and one random factor (subject). Subsequently, a Tukey multiple comparisons test is performed. Now I'd like to ...
2
votes
1answer
103 views

Post hoc test other than Tukey for factorial ANOVA data in R

I am looking for help on post-hoc tests of my group data (treatment and stage and interaction) after running a 2 way ANOVA in R. The data shown below is an example only. Actually my data shows ...
0
votes
0answers
27 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 ...
2
votes
2answers
146 views

Post hoc test for object of class glmerMod in R?

I am running generalised linear mixed effects models in R using the lme4 package. I am wondering if there are any post-hoc tests available for models built using the glmer function? I know the ...
4
votes
2answers
88 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 ...
1
vote
0answers
52 views

Which post-hoc comparison to use and why

Hopefully this is now a much clearer picture of the question I want to answer: For each of 60 different plans I ran 35 simulation replications of my Agent Based Model (ABM) simulation. Then for each ...
2
votes
1answer
67 views

Post hoc selection of important features in random forest?

I want to guarantee a parsimonious random forest (few features used). What are methods to do this? It was suggested to me to get the feature importance after the model was created, and then create a ...
2
votes
1answer
198 views

Post hoc $\chi^2$ test with R

This is a quite simple question but I don't find any good, clear, precise answers: I'm looking for a way to perform post hoc test on a chi$^2$ test. I have 2 variables : var1 : good/fair/poor and ...
3
votes
2answers
617 views

Can Mann-Whitney test be used for post-hoc comparisons after Kruskal-Wallis?

I have a simulation where an animal is placed in a hostile environment and timed to see how long it can survive using some approach to survival. There are three approaches it can use to survive. I ran ...