effect size

1. Power analysis and chi-squared control group sizes.

hello, Quite new to stats, I've asked one question on here before and received a lot of really helpful information. If I can be helped again I'd be really grateful. at my job, the senior management, want to have the smallest control group possible, in order to expose the maximum amount of...
2. Determining Effect size for Quade Test

Hello everyone, I did a Quade Test as a non-parametric alternative of the one-factorial repeated measures ANOVA, as my data are not normally distributed. My experimental design includes one factor having 3 levels (t1, t2, t3). All 28 subjects are confronted with all levels (t1, t2, t3) making...
3. effect size and significance

Does anyone knows about the relationship between the effect size and the significance? I was given following question and no clue how to answer it: You hear that a study (randomized, controlled trial with two groups) found a small sized effect of a drug (n = 72) against placebo (n = 72) of d =...
4. Obtaining the individual, relative variance contributions of fixed and radnom effects of an LMM in R

Hello, I am running a LMM (using the lmer4 package) with the following structure: lmer(Response~F1+F2+F3+(1|R1)+(1|R1:T2)+(1|R2)) For my research question I would like to quantify how much of the overall variance is explained by each indvidual fixed and each random effect. In other words I would...
5. Shapiro wilk effect size?

Hi, Like any other test, using only the Shapiro-Wilk p-value is sometimes useless., especially with a large sample size ... I did some searches and didn't find any suggested way to calculate the SW effect size. (and interpretation) Usually, the direction is to run the SW test (or other) and...
6. Cohen's d interpretation

The book says: 0.2 - small 0.5 - medium 0.8 - large I know that Cohen's interpretation is only a rule of thumb, so I'm not sure if there is a "one" answer. but what is the interpretation when d is between the values? Is d=0.3 small? or medium? Option 1 Range interpretation 0-0.2...
7. Sample size, effect size and power.

Hi all, I have a question I haven't been able to answer. I hope you can help me :). I use G power to estimate sample size. In my case, the estimated sample size for my desired effect size = 0.25 and power = 0,95, is 400. But the estimated sample size for an effect size = 0.5 and power = 0,95...
8. Effect sizes - Friedman's test

Hello, I have a question regarding which measure of effect size to use. For Friedman's test, do I report the effect size when the result of the test is insignificant? For example, Field (2014) only reports the effect size of the post-hoc tests, but not the effect size for Friedman's test. If I...
9. Conflicting definitions: What is “effect size” regarding customer churn?

One research paper says an example of "effect size" is the difference in the average age of churners vs. non-churners (41 vs 45). Another research paper says "effect size" is the difference in the area under the ROC curve (AUC was used to measure the validity of a model used to predict churn)...
10. Comparing differences between groups in different samples - which statistical test to chose?

Hello everybody I am doing some research in sleep medicine where I compare the test results of different sleep and vigilance tests. Within these different vigilance test results, the data is sorted in different patient groups. Since my data is non-normally distributed, I performed a...
11. GPower f (V) effect size interpretation

I am having difficulty understanding how to interpret effect size f(V) on GPower for a priori sample size calculation for ANOVA repeated-measures, within-between interaction. I am conducting an a priori power analysis to calculate sample size for ANOVA repeated measures, within-between...
12. Shapiro wilk effect size

Hi, Do you know how to calculate the effect size for Shapiro Wilk test? When using Shapiro Wilk test on a large sample, most likely it will reject H0 even for normally distributed population, since large sample will identify the minor effect as significant. Thanks :)
13. Effect Size - Cohen's D calculation

I had a question about how to calculate Cohen's D a particular situation for my meta-analysis. I am a first year grad student, so my familiarity with statistics is somewhat limited! The study design - participants are assigned to one of two groups (parallel design), but not a true RCT because...
14. Effect Size WRS2 package : Robust anova

pplying the one way robust Anova of the WRS2 package for a specific dataset I get the following results: > t1way(totspcam ~ bono_recibido, data = spend_red) Call: t1way(formula = totspcam ~ bono_recibido, data = spend_red) Test statistic: 49.4939 Degrees of Freedom 1: 2 Degrees of...
15. Cohen d and Z scores

Hi everyone, I should start by saying that I posted the same question that I will expose here on the psychological research forum. However, as I did not receive any answer, I wonder whether I misplaced my post. I apologize if this kind of repetition contravenes any of the rules of Talk...
16. Average effect size between factors and within an experimental condition

Dear all, I am interested in an average effect size between heart rate and anxiety. Anxiety is separated in 2 factors (F1 and F2), and I would like to combine the correlations of those factors into one correlation. In addition, I also have the correlations between heart rate and anxiety...
17. How to calculate effect size f-squared in PLS-SEM using R programming

Dear R experts, I am conducting a research using PLS-SEM approach using plspm package. However, I have no idea how to calculate effect size f-squared using R script in this case. Can anyone share some knowledge or any technical paper regarding this issue? I knew smart-pls software can...
18. comparing test results obtained on the basis of different sample sizes

I have variables a1 and a2 with 57 observations each, and variables b1 and b2 with 29 observations each. I compare a1 with a2 by means of a paired-samples t-test, this gives p<0.001. Next, I compare b1 with b2 by means of a paired-samples t-test, this gives p>0.05 (actually p>0.10). I compared...
19. Sensitivity analysis said I wouldn't find an effect less than .8 but I did!

Hello! I ran a sensitivity analysis on G*power and it told me that for my independent samples t test (10 people per group, alpha = .05, power =.8) I wouldn't find an effect size smaller than d = 1.32. I then ran the t test and got a significant result with an d = 1.15 How is this possible?
20. How can I intepret the effect sizes of Cramer's V when DF is high (like > 20)?

Dear All, I am doing Pearson Chi Square analyses in SPSS. Besides looking at the Chi Square Sig. value I also want to look at Cramer's V to analyze the effect sizes. My dataset has 12 million observations na I found a value of 0.12 for the Cramer's V. Standards for interpreting Cramer’s seem to...