"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
0answers
8 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
28 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 ...
0
votes
0answers
12 views

post hoc test other than Tukey of factorial Anova data in R

I am looking for help on post-hoc test of my group data (treatment and stage and interaction) after 2 way anova in R software. The data shown below is a example only actually my data shows significant ...
0
votes
0answers
19 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
1answer
48 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
46 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
41 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 ...
1
vote
1answer
46 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
46 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 ...
1
vote
2answers
109 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 ...
0
votes
1answer
61 views

$\textit{Post hoc}$ test after repeated measures ANOVA (LME + Multcomp)

I have a dataset where the samples are dependent, belong to different groups, and measurements were taken over time. It looks like this: Subject Group Time Value S1 G1 12h 5.55 S1 G1 24h ...
0
votes
0answers
21 views

How can I perform a post hoc test of a three-way interaction in SPSS using the 'test' command?

I will describe the design of the experiment briefly. The task have two within-subject variables ($A$ and $B$), A. have two levels B. have three levels one repeated variable with 5 levels ('time ...
0
votes
0answers
51 views

How to test signicance of differences between factor levels in mixed model using lme4 in R

My basic knowledge on model simplification comes from Crawley (2007) and I have also looked in Zuur et al Mixed Effects Models and Extensions in Ecology with R to try to answer my question. In ...
2
votes
2answers
92 views

Post-hoc tests for MANOVA

I am using a MANOVA test to compare nine different dependent variables (from neuropsychological and neuropsychiatric assessment) between three groups. The output shows a significant influence from ...
0
votes
2answers
50 views

What does a post hoc power analysis say about the significance of the study results?

I orginially posted this over at AskMetafilter, and a commenter suggested I ask it here. I work for a dietary supplement company that also makes skin care products, and some of those skin care ...
1
vote
1answer
71 views

Cochran's Q & McNemar tests together

I have binomial outcome data for three groups that I am analyzing with Cochran's Q test. As discussed at this site, Cochran. However, I have to repeat this seven different times because I am ...
0
votes
0answers
31 views

Post hoc split plot design

I have an experiment in which I have four fenced large plots. I subdived every fenced plot into three smaller fences to have three grazing levels. Within every grazing level I planted 20 saplings ...
0
votes
0answers
21 views

Obtaining Cohen's d from z-test statistic

After an ANOVA, I run post-hoc tests with the glht function in the multcomp package. glht ...
0
votes
0answers
17 views

Follow up a significant interaction in ANOVA with dichotomous variables

Hopefully this is an easily answerable question, though I've been searching for an answer without any luck. I've run a 2x2x2x2 mixed-design ANOVA with two within-subjects and two between-subjects ...
1
vote
1answer
84 views

Doing post-hoc after a not significant interaction in mixed ANOVA

I conducted a mixed design ANOVA with two within-subjects factors: FactorA (2 levels), FactorB (2 levels), and one between-subjects factor: Group (2 levels). My main hypothesis regards the interaction ...
1
vote
0answers
21 views

Kruskal-Wallis test for factorial design [duplicate]

Is it possible to use the Kruskal-Wallis test for two factors and their interaction (i.e., two way ANOVA: Y~a*b)? And which post-hoc test is possible to use after ...
2
votes
1answer
39 views

R multcomp: contrasts for Tukey

I want to use the glht() function from package multcomp. In the linfct argument, I provide ...
1
vote
1answer
74 views

2x2 ANOVA, no main/interaction effects, post-hoc cell mean comparisons necessary/allowed?

I have a 2x2 between-subject design with unequal cell sizes. I ran an ANOVA with type I sums of squares to account for the unequal cell sizes. Neither of the two main effects nor the interaction ...
2
votes
2answers
58 views

How to find significant difference in a group/ ANOVA

Am I right to say that the results from the a repeated measures ANOVA does not tell you where a difference is in the group (if any)? So a post hoc test needs to be carried out? I'm using Stata to ...
0
votes
1answer
41 views

post-hoc test after logistic regression with interaction. Risk higher for type 1 or type 2 error?

I have a large data set (>1000 obs) and i'm performing regressions tests, both linear and logistic, on a series of clinical outcomes. In this test I verify the effect of interactions between two cat ...
0
votes
1answer
44 views

Post-hoc test for slopes - phia package for R

I am trying to do a post-hoc test to make pairwise comparisons between slopes. I found a package called phia but is not available for the R version 2.13.2. Does ...
2
votes
1answer
33 views

How to deal with non-normal heterocedastic data from a factorial experiment?

I ran an experiment with two factors each with two levels, 5 replicates each combination and one response variable. My data are non-normal and heterocedastic. Transformations didn't help. I ran a ...
0
votes
1answer
69 views

ANOVA and post-hoc analysis using R when we only have means and SD of three populations

I want to perform an ANOVA using R. I have three populations, represented by their respective means and SD: Pop.1: 5.5 +- 0.4 (n=100) Pop.2: 5.9 +- 0.3 (n=150) Pop.3: 6.2 +- 0.5 (n=200) Which is the ...
0
votes
0answers
31 views

Approach to post-hoc test for factors in a regressions (in R)

I have a problem with some analysis I need to do. I have a series of regressions. Some of the predictors of these regression are categorical with multiple levels. I performed regressions, both linear ...
2
votes
0answers
38 views

MANOVA vs repeated measues ANOVA example

I have the following situation (4 independent treatment groups, each group is tested for 3 dependent variables) and was wondering what would be the best to do: What is the best test to do? I have ...
1
vote
0answers
69 views

R - Post hoc comparisons in 2x2 ANOVA unequal sample sizes

I have a 2x2 between-subject design with (slightly) unequal cell sizes. Hence I chose to use the anova(lm(...)) function so that Type 1 SS are used: ...
-1
votes
1answer
62 views

Equivalence testing vs ANOVA post hoc tests

How is statistical equivalence testing different from post hoc tests done after ANOVA?
2
votes
2answers
98 views

Why test for both correlation and groups differences using the same variable?

A paper asks four research questions which deal with the measurement of latent trait x, a continuous variable which is acquired through learning or practice, and the speed with which the knowledge or ...
1
vote
0answers
67 views

lme vs lmer vs aov for three factor repeated measures design

I'm trying to run a tree-way repeated measures ANOVA on the following data: I have a completely balanced design with three within-subject factors (type, form and ch - channel) and one dependent ...
2
votes
1answer
175 views

Post-hoc tests on linear mixed model give mixed results.‏

I am quite new to R so apologies if I fail to ask properly. I have done a test comparing bat species richness in five habitats as assessed by three methods. I used a linear mixed model in lme4 and got ...
0
votes
0answers
47 views

Post-hoc analysis of 3 sample prop.test

I am looking for the correct way of performing post-hoc analysis on the results of a 3-sample test for equality of proportions and haven't been able to find anything specific to this test. The data I ...
0
votes
0answers
34 views

Appropriate post-hoc test after a mixed design anova in R [duplicate]

I have a mixed design ANOVA, with a 2 level between-subject and a 7 level within subject variable. What is the appropriate post-hoc test after a significant ANOVA? I'd like to see R code in the ...
0
votes
0answers
25 views

Interpreting the results of post-hoc ANOVA

After concluding from a one-way ANOVA, that a variable (country) is indeed statistically significant, I conducted Tukey's multiple comparison post hoc test. Here is the plot for mean Cost (DV) vs ...
5
votes
1answer
60 views

Power analysis for post hoc test of ANOVA with many groups

In both G*Power and the R pwr package, estimated sample size required per group decreases as the number of groups increase. This seems somewhat counter-intuitive. For a toy example, assume that I ...
0
votes
0answers
40 views

Which post-hoc test should I use after finding significance in two-way within subjects ANOVA?

I have tested 3 treatment conditions on 7 scenarios where each scenario had 7 trials (each for 20 subjects). After running an ANOVA (...
1
vote
0answers
61 views

R: Post hoc tests in ANCOVA with factorial design

Does anyone know how to do post hoc tests in ANCOVA with a factorial design? I have two vectors consisting of 23 baseline values (covariate) and 23 values after treatment (independent variable) and I ...
1
vote
1answer
62 views

In the output of lsmeans, is “estimate” is effect size of that contrast?

I am using lsmeans to run post-hoc analysis for contrasts of linear mixed model, and here is the output: ...
0
votes
0answers
16 views

posthoc test for a within-subject factor in spss

I am doing MANOVA. I have a within-subject factor "fatigue". One variable is fatigue (baseline, fatigue, rest). One of the dependent variable is the amplitude of swallowing muscle activity (T_tot_d ...
0
votes
1answer
188 views

Interpreting a significant 2-way interaction with post-hoc tests

I'm analyzing reaction time data from a repeated measures ANOVA with the following design: Factor 1 (between-group): GROUP (controls, clinical) Factor 2 ...
0
votes
0answers
37 views

post-hoc test on mixed-effects model

I have an experiment with bacteria for which I measured growth curves of several bacterial clones in two different types of media (treat). I then extracted several growth parameters from the curves ...
0
votes
0answers
13 views

Chi goodness and Fishers: some theoretical issues post-experiment

I have run a simple experiment under four conditions: the Control, Technique A, Technique B, and Technique C (which is a+b) The dependent variable is compliance (e.g. Yes/No) These are my results ...
0
votes
1answer
289 views

Post-hoc Tests for Fisher's Exact Test

I am running a series of Fisher's test to analyse some 2x2 contingency tables with small values. I have found significance. Is there anything equivalent to Cramer's V or the Odds Ratio or some sort of ...
1
vote
0answers
121 views

Analysis of rates and post hoc test with offset variable using glmer.nb

I am investigating variation in pollinator visitation rate (number of visits per inflorescence) with treatment and time category as fixed factors. Block is a random factor. Following Zuur et al. ...
0
votes
0answers
18 views

Multiple comparisons with Dunnetts t3 or Dunnetts c

I have a dataset with un-even variance and un-equal class sizes (This was a random sample of land cover classes). After using ANOVA to determine significant differences exist among classes, I ran ...
0
votes
0answers
16 views

Need help with value for number of measurements and correlation among rep measures in G*Power repeated measures within-between post-hoc

I am looking to find the power of a study using a G*Power post-hoc test for a repeated measures within-between design. I have the effect size calculated, alpha set at .05, my sample size, and number ...