effect size

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...

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...

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 :)

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...

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...

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...

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...

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...

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...

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?

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...

Hi there, I am designing a study that compares three conditions (differences in glass shape) on one main DV (drinking rate) (as well as some secondary DVs). I want an adequate sample size to be powerful enough to test the primary hypothesis, that there will be a difference between the three...

Hi everyone, I am writing a paper for publication. This is my first time doing a survey study, and also my first time working with categorical data (I, like many people unfortunately, have learned statistics bit by bit, as I have needed it in my research). The journal I am submitting to...

Hey everyone! I conducted a simple linear regression with non-significant results. Now I would like to analyze the power of this calculation using G*Power. I chose the option "F-tests - Linear multiple regression, fixedmodel, R(2) deviation from zero and entered 1 as my numer of predictors...

hi everyone, I would like to create a Forest plot for a number of studies that looked at proportions. I calculated effect sizes using Cohen's H, but now I need to know the confidence intervals for those effect sizes. Does one of you know how to calculate those? Thanks in advance!

This may seem like a ridiculous question, but it's bugging me and no text book or paper I've read has answered it. I am looking into research on effect sizes and their use in research. I see a lot of mention of Cohen's D and F2 and the "small", "medium" and "large" effect sizes. Can someone...

Hello, I am trying to figure out the best way to calculate an effect size for a single-group design when I do not know the pair-wise correlation or standard deviation for the difference scores. I have received mixed messages as to whether or not I can use the formula for independent measures...

My question is about calculating effect sizes for a repeated measures design with a small sample size. I want to calculate Cohen's d.av (as recommended by Lakens, 2013 and others) instead of d.z (which you can compute using just your t-value and N), since the latter tends to overestimate your...

Is there a simple formula that links effect size, sample size and p-value? Specifically, how does the p-value depend on effect size and sample size? Are there any other critical factors involved in this relationship? I'm basically looking to understand how these factors are linked...

I'm a bit desperate for statistical help so trying out all avenues. Any guidance appreciated! I need to justify a sample size of 30 or 32 (15 or 16 per arm) for a placebo-controlled pilot clinical trial of a drug. This is all I can afford, but that is not a good enough justification for...