Tagged Questions

44 views

eta-squared by hand

This code outputs the eta-squared from an ANOVA: ...
83 views

How to calculate cumulative standards errors from several ones?

I want to estimate the cumulative effects of air pollution on mortality using GLM or Gam methods. With the following R code I was able to estimate the cumulative effect of PM10 on mortality which is ...
33 views

Calculating effect size variance from adjusted means (or least squared means)

I have a question related to this post regarding the calculation of the variance of an effect size. In my specific case, I would like to calculate the effect size and its variance from adjusted means ...
48 views

Calculating Effect Size in R

I've been trying to learn about effect size in relation to linear regression and am wondering how to implement it in R. Sure, I have p-values and they indicate how "predictive" the explanatory ...
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Controlling for medication effects in case-control comparison

Say as an example problem you are comparing BMI between two groups, one group is healthy (CTL) and the other has been diagnosed with bipolar disorder (BPD). Some of the BPD patients are taking a ...
81 views

Partial $\eta^2$ for repeated measures ANOVA (with R's car package) [closed]

I have a 2-way repeated measures design (3 x 2), and I'd like to get figure out how to calculate effect sizes (partial eta squared). I have a matrix with data in it (called a) like so (repeated ...
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Translating R code about treatment into Effect size. Expected mean and variance

Using R, I created groups of individuals with trait values. Then I simulated a treatment that modified their trait value (see below). Finally I run a one-way Anova on them using the individuals traits ...
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How to best handle subscores in a meta-analysis?

I am conducting a meta-analysis of effect sizes d in R using the metafor package. d represents differences in memory scores between patients and healthy. However some studies report only subscores of ...
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Computing $\eta_P^2$ from $\eta_G^2$ generalized eta for G*Power

I am trying to perform a power calculation using G*Power. I need $\eta_P^2$, but the ez package for R gives me $\eta_G^2$. I understand the reasons for it doing this, but I still need $\eta_P^2$ for a ...
91 views

Pretest-posttest plus control design

I am evaluating the effect of an intervention (treatment: a lecture) on the ability to spot behavioral clues of emotions using visual stimuli using pretest-posttest plus control group experimental ...
131 views

Confidence interval of the ratio of two means for very small sample sizes

I have an experiment with 3 tanks for, both, treatment and control. I have used a natural logarithm of response ratio (LnRR) with 95% confidence intervals to examine the effect size of the treatment ...
287 views

Standard deviation for adjusted effect size estimates

I am trying to calculate the effect size for a trait adjusted for my set of nuisance variables. My models looks like this: Trait ~ Dx + Age + Sex Where "Trait" ...
280 views

Effect sizes from LMM

My question is, how to get effect sizes for a linear mixed model? I am using the following model in SPSS: ...
93 views

Which 'delta' to use from those returned by 'orddom' package in R with argument 'paired = TRUE'?

I have used the orddom package in R with the argument paired = TRUE to calculate the Cliffâ€™s delta for paired groups, and a ...
44 views

Significance and effect size in treatment design when treatment-response in measured

I have a number of plants and all of them undergo a 'treatment'. Then I measure the amount of plants that react to the treatment and the amount that do not. Is there a way to calculate a test ...
42 views

Simple similarity comparison over time

I've seen that Pearson's r is typically used for evaluation between non-experimental conditions. However, I've also seen Pearson's r used to indicate effect size - is this acceptable? Is it a useful ...
316 views

Implementing McKelvey & Zavoina R2 for drc package in R

I'm implementing the McKelvey & Zavoina pseudo-R2 measure for use with the drc package and intend to open-source the solution and contribute to that project. I ...
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Articles that describe formulas of how to calculate confidence intervals for the omega-squared effect size?

I'm looking for articles that describe methods of how to calculate CIs for the omega-squared effect size from an one-way ANOVA. The closest I've come is Finch & French (2011) A Comparison of ...
676 views

Effect Size/Mean Squared Error from Linear Mixed-Model in R [duplicate]

I'm trying to report an effect size for a Linear Mixed-Model we've fitted in R. Right now I'm looking at reporting partial eta squared or eta squared. However, to do so I need to calculate the Sums of ...