Questions tagged [tukey-hsd]

Tukeys Honest Significant Difference (HSD) is a multiple comparison method based on the studentized range distribution.

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9 views

How to select lines within Tukey's test result?

This mays be a dumb question, but I'm kinda of stuck. I've got a .csv data files organized in Year, Month, Day and Likes helping me analyze my Instragram account (yeah I'm a bit bored but basically I'...
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16 views

Post hoc test after Chi square, please advise

I am analyzing a questionnaire survey data about online learning receptibility across different age groups. I have 4 age groups, and each has its % acceptance of the online learning susceptibility. ...
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23 views

Why do I get different results for Tukey HSD compact letter comparisons with different R packages?

I have a dataset that I have been trying to run Tukey HSD tests on and obtain a compact letter display. I originally used the agricolae package with function ...
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48 views

Comparing different samples from different years: ANOVA?

I have been collecting data for 10 consecutive years. Once in each year different participants (N=110/Year) had to rate the importance of each one of 30 different social values, on a Likert scale (1-5)...
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25 views

Why is the Tukey method not appropriate for covariance analysis when estimating treatment effects?

In the book 'Applied Linear Statistical Models' chapter 22 it states that the Tukey method is not appropriate for covariance analysis. The context is in estimation of treatment effects. Instead, when ...
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1answer
28 views

Strange output for pairwise comparisons on glm with quasi-binomial distribution

I'm new to CrossValidated - I've read up on how to ask questions properly but sorry if I do anything slightly wrong. My data is showing whether microplastics were present or absent in the gut of fish ...
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1answer
64 views

Anova and Tukey HSD vs Linear Regression

When analyzing the difference in means between $k$ groups, a one way ANOVA is equivalent to a simple linear regression with indicator variables for group membership $$ Y = \beta_0 + \beta_1X_1 + \...
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19 views

anova and tukey reporting

I have an ANOVA with a numerical score as the DP and a category as an IV: model = aov(score~group, data = dat) And then I run a Tukey: ...
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28 views

Statistical question about ANOVA, Tukey and t-test (also R-related)

I am new to statistics and have to do some analysing for a beginner project. However, I am so confused right now and have nobody that I can ask. About the project experiment: We conducted a between-...
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14 views

Determining Significance in AxB Anova with repitition

I am looking to understand how the best method of determining the individual significant between my interactions would be calculated in a Two Way anova with repetitions. Based on the results of the ...
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17 views

To read a Tukey result for a GLM model

Here is the Tukey test result I get after interpreting a model, but I'm not sure what it means, can someone help, please? Thank you so much! Here's the result interpretation:
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9 views

Conflict in Tukey's HSD value

I have run post hoc mean comparison analysis by augmentedRCBD() command in R. Results are as follows: ...
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16 views

ANOVA testing for User Activity on a website

Problem: I am trying to determine whether visitors on a web-site are more likely to perform a certain action (click a specific button in this case) if they view a specific section on the website. I ...
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1answer
53 views

Do you need to adjust p-values after Tukey's HSD? How to do this correctly?

I have multiple sets of comparisons I am running together. Normally I would do an FDR correction on the p-values to control the family-wise error rate. However, the p-values from a Tukey HSD are ...
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1answer
33 views

Checking ANOVA for unbalanced data

I would like to figure out if there are significant differences between the following groups. I use R: ...
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8 views

Tukey's HSD over hundreds of variables

I have a list of conversations taking place between two people. I am counting the number of overlapping words at varying points in each conversation. This has given me a long list of numbers (5500 ...
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26 views

Differences between years in time series data

I have a multiyear time series dataset detailing the concentration of environmental contaminant over time. and I need to determine if there is a significant difference between the yearly means. In ...
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5 views

What test adapts to this situation

Hello im trying to use sigmaplot and do a one way ANOVA and a comparison to a control group this is to a problem of an enzimatic production by the same organism in prescence of a drug at diferent ...
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1answer
53 views

Why is one mean not significantly greater if every element is greater than the other group?

the mean of group C and every element in group C is greater than its row-wise peers. Why is the Tukey comparison giving insignificant P-values? ...
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182 views

ANOVA: life after rejecting the null hypothesis

I have multiple groups of data (20+ groups) and test the null hypothesis that they have the same mean. How do I proceed after the null hypothesis is rejected? What is the standard method for selecting ...
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1answer
693 views

Does R use Tukey or Tukey-Kramer test corrected for unequal sample size and does it use the multivariate t distribution?

Does R use the classic Tukey HSD test for balanced data or corrects for unbalanced ones with the Tukey-Kramer approach? I mean the stats::TukeyHSD(). I found, that the Dunnet procedure uses ...
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1answer
244 views

How is the standard error used in calculating a Tukey HSD defined and calculated?

I am looking at someone else’s published data where they report treatment means and then a single standard error value across treatment means. I want to know if certain treatments are significantly ...
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1answer
556 views

How do I report results from a Tukey post hoc analysis?

I examined all possible comparisons in the Tukey test (here is the chart - sorry it's a little unclear) https://scontent.fybz2-1.fna.fbcdn.net/v/t1.15752-9/...
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1answer
39 views

Default multiple comparison correction in TukeyHSD in R? [closed]

Does anyone know what the default method is for adjusting for multiple comparisons is in the TukeyHSD function? (e.g. BH, Bonferroni, etc.)
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73 views

p-value calculated using ptukey() does not agree with p-value obtained from TukeyHSD()

I have the following toy dataset group1=c(1,2,3) group2=c(5,6,7) group3=c(2,4,6) ex1=rbind(group1,group2,group3) ex1=melt(ex1) I build an ANOVA model, solve it, ...
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82 views

emmeans/multcomp in R vs multcompare in Matlab

I am analyzing a dataset with one within variable (Xw1) and one between variable Xb1. The within variable (...
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91 views

How can I compute a confidence interval on Cohen's d derived from a Tukey HSD contrast?

Question Background Consider for example that I have some data arrayed as a 1-way (Group: A, B, C, D) between groups ANOVA. Consider further that I am interested in all possible pairwise contrasts ...
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44 views

Interpreting Tukey HSD grouping results with one item interacting in multiple pairwise comparisons

I'm looking for help on how I should go about interpreting/concluding the outcome of my post-hoc Tukey HSD analyses. I'm trying to discern if the 12 operational efficiency groups I'm reviewing for a ...
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1answer
523 views

Calculate Cohen's d for pairwise tukey tests in a 1-way ANOVA

I have the following dilemma: Design: 1 (Group: Patient vs. Control_1 vs. Control_2) between-factors design arrayed as a 1-way ANOVA Analysis: Following a main effect of group perform I perform all ...
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1answer
35 views

Are there any situations where ANOVA performs better/is more useful than Tukey's HSD?

In statistics this week we are learning about ANOVA and Tukey's HSD. If ANOVA only tells you whether the differences in the means of the groups are significant, but Tukey's HSD gives you the ...
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23 views

Multiple comparisons from means and standard deviations

I am attempting to do a statistical comparison of the mean concentrations of certain ingredients between different varieties of a product, based on summary data. An example table depicting the type ...
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2answers
137 views

How to select the best variant from an A/B/C test?

Suppose I've run an A/B/C experiment (same as A/B but with 3 groups instead of 2) and gathered the following data for number of participants in each group and number of desired actions in each group (...
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73 views

Post Hoc Tests with a lm model where model assumptions are violated

I have the following data set: dependent variable is carbon levels in manure. Independent varibale is the month that the manure was collected in (12 level factor). I want to test if there is a ...
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26 views

For microbiome data, is there a way to stratify within Tukey HSD?

I have Shannon diversity metrics for samples that are repeated measures collected over time with different genotypes and I would like to stratify the Tukey by the collection time. ...
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1answer
77 views

Using pairwise comparision on gls object [closed]

I have one factor (tree genotype) and I analyse its influence on soil content. I used gls to aply weights on my data because it's a better fitted model. Here is an exemple of my data with one ...
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1answer
50 views

Splitting groups for statistical comparisons

I have a question that I cannot answer based in my biological background. I conducted one experiment with 5 replicates and 4 treatments. There were two goals: the first goal was to elucidate if our ...
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1answer
14 views

Tukey Kramer and the reduction of type one error

I hope everyone is doing well. I understand that the Tukey Kramer reduces the chance of getting a type 1 error by using a pooled variance. That pooled variance then gives you a lower standard error ...
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1answer
251 views

TukeyHSD p-value is less than t-test p-value

I have some data where when I do t.test for a specific pair of groups, the p-value is (barely) higher than when I do TukeyHSD ...
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1answer
1k views

How to calculate Tukey-adjusted p-values for emmeans pairwise comparisons?

I would like to calculate Tukey-adjusted p-values for emmeans pairwise comparisons. I know that these can be obtained directly with functions like pairs() and CLD(). However, when there are three ...
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2answers
50 views

Multiple comparison problem

If I conduct 19 tests (e.g. 19 pairwise comparisons of treatment means in an experiment), what is the probability that I will find at least one P value < 0.05 due to chance alone? With number of ...
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1answer
221 views

Anova of a mixed effect model (lmr) shows no significant interaction while tukey (emmeans) does?

I have run a linear mixed-effects model using lmer package. I'm using year sampled (1990s or 2017), field(1967 or 1984), and treatment (open or closed) to determine differences in native herbaceous ...
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2answers
999 views

Interpreting a Tukey - Kramer Confidence Interval Plot

In order to see if any statistically significant differences in the means of 4 particular diets exist, a post-hoc test is conducted i.e. Tukey – Kramer. Could someone please explain to me the plot ...
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552 views

Using pairwise comparison on gls object with heterogeneity of variances?

I'm comparing total yield from fields under 5 different treatments. As you can see, the variance differed between the treatments (diagnostics from lm() fit): So I ...
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1answer
58 views

How to conclude that all group means are different?

Suppose I have groups $G_1$ to $G_n$ with sample means of the variable of interest $m_1$ to $m_n$ respectively and sample variances $s_1^2$ to $s_n^2$. What tests can I perform to conclude that the ...
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1answer
385 views

What post-hoc analysis should I use following a two-way ANCOVA with factor, integer and numeric variables?

I ran a two-way ANCOVA on the data below, in r-studio, to determine whether pupal weights Pupal.wt were affected by caterpillars' diet ...
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695 views

Pairwise comparisons after ANOVA with Tukey and Bonferroni methods in r

The built-in functions TukeyHSD and LSD.test from R perform pairwise comparisons. In order to maintain the type I error, the significance level $0.05$ is divided by the number of comparisons $k$. Do ...
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1answer
88 views

How to show specific results in R using Tukey test?

I have a question about showing specific results in R. I am using a linear mixed model and checking the stats between each condition (adding 1, then adding 2, then adding 3...) in a repeated test, ...
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0answers
34 views

Simple GLM analysis on Springtail Community Dynamics: determining which variables affect Abundance

I'm looking at Springtail community analysis and want to see what, if any, affect Litter Type (LT), Site Type (ST), and Sampling Day (SD) have on springtail abundance. LT and ST both have 3 factors ...
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1answer
493 views

Adjusting p-values for multiple ANOVAs

I am performing multiple (around 40) multi-way ANOVAs on a dataset, one for each outcome variable. There are three factors involved: cohort, pre/post, and tissue type. For each outcome variable, I ...
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1answer
545 views

Which is right to perform a Tukey post hoc in R? [closed]

I know 3 ways to perform a Tukey post-hoc test in R and the results are a little different. Initially, I performed a two-way anova ...