Questions tagged [anova]
ANOVA stands for ANalysis Of VAriance, a statistical model and set of procedures for comparing multiple group means. The independent variables in an ANOVA model are categorical, but an ANOVA table can be used to test continuous variables as well.
67 questions from the last 365 days
3
votes
2
answers
81
views
Are the aov Confidence Intervals Valid?
Can you please inform if these 95% confidence intervals of AOV (Analysis of Variance) models are valid?
I was expecting them to lead to the same results as lmer objects, but that does not always ...
- 31
3
votes
1
answer
57
views
Using contr.sum for Type III ANOVA but contr.treatment for reporting regression coefficients in R – is this reasonable?
I am analyzing a 2×2 factorial design in R with two categorical predictors (Bewirtschaftung and Bodenstoerung) and a continuous ...
- 415
8
votes
3
answers
255
views
Appropriate approach for checking concentration change for 80 substances with n = 3 for three time points
I am relatively new to statistics and would appreciate some guidance on whether my analysis approach is appropriate.
What I have:
I measured concentrations of 80 different substances. There are three ...
- 91
4
votes
2
answers
127
views
Should I keep the interaction test in this comorbidity stigma study?
I am running a 4-group vignette study: Control, Condition A, Condition B, and Comorbid A+B.
I chose this design because A+B is common in real life, and I wanted to test whether the comorbid ...
1
vote
2
answers
61
views
Reporting results from Type III ANOVA vs. summary(lm()) estimates in a bachelor thesis
I am currently writing my bachelor thesis and I am a bit confused about how to properly report results from a factorial ANOVA in R.
I fitted a linear model with two factors and their interaction and ...
- 415
2
votes
1
answer
45
views
Semantics: planned comparison and pairwise comparisons following ANOVA
Is the term "pairwise" still used in the context of planned group comparisons?
E.g., "two sets of planned pairwise group comparisons were performed".
Versus
"two sets of ...
- 65
0
votes
0
answers
26
views
Effect size for non-significant Type III ANOVA: ω² vs. raw-scale differences
I conducted a Type III ANOVA for my bachelor’s thesis using R (car::Anova), as my design is unbalanced (one missing value) and includes an interaction:
...
- 415
0
votes
0
answers
26
views
Questions about calculating effect sizes for post-hoc comparisons after ANOVA/ANCOVA
I ran several tests comparing levels of two types of IQ (verbal IQ and math IQ) across 4 groups (group A, group B, group C, and group D). For verbal IQ I first ran ANOVA to assess group differences, ...
2
votes
1
answer
96
views
Can I use Bonferroni correction on post-hoc tests using Fisher's LSD?
When I typically run ANOVA or nonparametric ANOVA or ANCOVA in SPSS to compare groups on some DV, SPSS gives me the option to use Bonferroni correction for post-hoc tests. I just used SPSS to run ...
5
votes
4
answers
278
views
How to specify contrast for interaction in mixed anova with 3 conditions and 2 groups
20 people are divided into two groups (between subject variable) - 12 and 8 members in each. Each person is measured under 3 conditions (within subject variable).
I am using means model ...
- 4,030
0
votes
0
answers
64
views
LME vs. RM ANOVA for Spatial Localization: Defending trial-level models..what?
I would appreciate a sanity check on whether my Linear Mixed Effects (LME) approach is defensible or if I should revert to a standard Repeated Measures (RM) ANOVA (what's used conventionally in the ...
- 1
2
votes
1
answer
86
views
ANOVA reporting appropriate effect size
I fitted a ANOVA type II model:
po_o <- aov(Porosität ~ Heuen * Wühlmaus, data = df_1)
po_II <- Anova(po_o, type = "2")
The result is not ...
- 415
6
votes
1
answer
106
views
Two-Way ANOVA with Missing Observations: Type I vs. Type II Sums of Squares
I am currently writing my bachelor’s thesis and have only a limited background in statistics.
I have four groups with four observations each, except for one group which contains only three ...
- 415
2
votes
1
answer
86
views
Difference between ANOVA and the use of qualitative variables OLS
I'm new to statistics, and recently I have learned how ANOVA works and I was left thinking. Can't we do the same thing we do in ANOVA using qualitative (dummy) variables in regression with OLS?
The ...
- 23
2
votes
1
answer
41
views
How to compare two results having unequal large number groups each and within sub-groups having members from 1 to 16 [closed]
I want to compare two groups of results (let's say A and B), acquired from image population of 1154 by using two process/models for re-identification.
Each group (A and B) contains sub-groups ...
- 31