Questions tagged [effect-size]

Effect size is "a measure of the strength of a phenomenon or a sample-based estimate of that quantity" [Wikipedia].

Filter by
Sorted by
Tagged with
0 votes
0 answers
9 views

Linear mixed model: How do z-standardized coefficients relate to effect size?

I have a very simple linear mixed model: Y ~ condition * rating + (1|subject). Condition is a factor with 3 levels and coded using treatment contrasts. Hence, I compare level 1 and level 2 with level ...
user avatar
  • 29
2 votes
1 answer
31 views

What is the effect size `h` in `pwr::pwr.p.test` in `R`?

The R package pwr has a function for calculating the required sample size for a one-sample proportion test (I assume a z-test ...
user avatar
  • 32.4k
1 vote
1 answer
21 views

Can a consensus be reached on the exact meaning of "Cohen's D" and "Hedge's G"?

This question: Difference between Cohen's d and Hedges' g for effect size metrics shows there are at least two different interpretations each of both Cohen’s D and Hedge’s G, one of them in ...
user avatar
0 votes
0 answers
9 views

How to calculate effect size for impact measurement in a quasi-experimental study? [closed]

I have baseline and endline mean scores and standard deviations, respectively, for a treatment group and comparison group (4 sets of data each for control and treatment). I need to calculate the Cohen'...
user avatar
  • 1
2 votes
1 answer
26 views

Determining direction of effect in Wilcoxon Test and interpreting pseudomedian in R

I originally posted this on Stack Overflow (https://stackoverflow.com/questions/72649894/determining-direction-of-effect-in-wilcox-test-and-interpreting-pseudomedian), but I realized it fits better ...
user avatar
  • 41
0 votes
0 answers
11 views

Design of Experiment, sample size and repitition

When designing resp. performing an experiment, I'd come up with something like this finally: A question of such an experiment is whether to include repetitions, where you'd simply repeat the entire ...
user avatar
  • 2,207
2 votes
0 answers
53 views

Meta-analysis in R: multiple effect sizes with unknown correlation

I'm working on a meta-analysis with multiple effect sizes reported in most studies. My effect sizes are SMD between two groups (health/ disease) and the reason there is multiple effect sizes per study ...
user avatar
  • 21
0 votes
0 answers
13 views

Detecting statistically significant change between multinomial samples and individual category proportions

Say I have a categorical variable with more than two categories, e.g., a person's country of origin. Assume the number of categories is some finite $k$ (e.g., not dealing with distribution of people'...
user avatar
  • 151
3 votes
1 answer
162 views

Why I can recover the total effect with OLS but not with logistic regression?

The dataset ISLR2::Default contains one observation per individual. The variable Default is "Yes" if the individual ...
user avatar
1 vote
0 answers
12 views

Effect size and statistical significance correspondence

While I understand that it is possible to have a small effect size with statistical significance and a large effect size without statistical significance, is it ever possible to find this across two ...
user avatar
2 votes
1 answer
77 views

Building a bootstrapped distribution to test reliability of empirical data

I have data from a study where subjects (considered as "generations" in a Telephone-like game) sang short melodies from one to the next, starting from a randomly-generated melody (seed) ...
user avatar
  • 1,560
0 votes
0 answers
9 views

Calculating global and local effects in a multiple regression using Cohen's d

I am calculating the effect size Cohen's d using linear regression. I am looking at the effect of disease on memory, and have also added age, education and sex as confounds to the regression. Cohen's ...
user avatar
  • 121
0 votes
0 answers
46 views

lmer anova effect sizes

I would like to compute the marginal R squared for the whole factors from an anova table. This post shows how to get the effect size for each fixed effect based on the ...
user avatar
  • 639
0 votes
0 answers
17 views

Meta-analysis with ratio data

I am currently performing a meta-analysis where the outcome of interest is the ratio between the concentration of two sugars in urine/plasma (i.e. the results of dual-sugar test; see: https://doi.org/...
user avatar
0 votes
0 answers
16 views

Effect size calculation on a MANOVA with contrasts

I would like to conduct a repeated samples (patient) ANOVA (with Factor X with 3 levels A, B, C) with the planned contrasts (A+B)-C (i.e 1 1 -2) and (A+C)-B (i.e 1 -2 1) as well as calculate the ...
user avatar
  • 13
0 votes
0 answers
8 views

How are effect sizes calculated following a cellwise residual analysis?

I have used SPSS to create a 2X4 contingency table concerning the relationship between two categorical variables: depression diagnosis and 4 sleep disruptions. I carried out a chi square test of ...
user avatar
2 votes
1 answer
34 views

Spearman's Correlation and effect size

I have completed data collection and I have a Spearman's correlation of .64. My advisor is wanting me to report the effect size and from everything I have read and can find it appears that .64 would ...
user avatar
0 votes
0 answers
20 views

How should I calculate effect sizes for a 2X4 table?

I have used the software SPSS to produce a 2X4 contingency table, using categorical data. I am aware that odds ratio is only applicable for 2X2 tables. Are there alternatives to odds ratio to try and ...
user avatar
0 votes
0 answers
26 views

Intuitive effect size (and CI) for one-way comparison of group means?

I'm a big fan of common language effect sizes (e.g. McGraw and Wong's CL or Cohen's U3 - "what proportion of group 1 are higher than the average for group 2"). I've been scrabbling around ...
user avatar
  • 691
2 votes
0 answers
33 views

Effect size: difference between Cohen's d and Wilcoxon's r?

In the simple case where I have N trials with mean result $\mu$ and I want a measure of how on the whole they differ from a theoretical model of a normal distribution with mean 0 and standard ...
user avatar
  • 121
1 vote
0 answers
14 views

Cohens d in relation to a single case

Cohen's d in relation to a single case The average effect size (Cohens d) for insomnia-treatments ranges from about 0.3 to 0.4. If I had a patient that suffered from insomnia 4 out of 5 weekdays (...
user avatar
1 vote
0 answers
19 views

How was effect size calculated in this study?

I am trying to learn about effect sizes and how it relates to real-world data so I looked at a random study for insomnia-treatment: https://onlinelibrary.wiley.com/doi/10.1111/jsr.12067 and the ...
user avatar
0 votes
0 answers
20 views

Convergence algorithm for power analysis?

I found this algorithm on a shared drive and I'm really curious how it works. From appearances, it's used to estimate the MDE in power analysis when the effect size (difference of proportion means) ...
user avatar
  • 1,634
0 votes
0 answers
21 views

In a 1-way ANOVA, is the square-root of the coefficient of determination the intra-class correlation?

The actual question I mean to ask is if the square-root of the effect size is the intra-class correlation (ICC). When the 1-way ANOVA test is viewed as a bivariate analysis between a categorical ...
user avatar
  • 3,883
0 votes
1 answer
40 views

Conflict Between Confidence Interval and P-values - One Sample T-Tests

I'm conducting one-sample t-test using R. I calculated p value, effect size, and confidence interval, but they seem to be conflicting. Here is a sample code and output: ...
user avatar
  • 69
0 votes
0 answers
19 views

Effect size calculation?

We are currently analyzing medical records data. During the study period, we have a minimum of 60,000 population patients in group ...
user avatar
  • 603
0 votes
0 answers
27 views

Power analysis: How do you calculate the power (1-B) based on the matched-pairs biserial correlation effect size?

I am running a Wilcoxon-signed rank test, and as suggested by King et al., the best effect size to report for this analysis would be the matched-pairs rank biserial correlation. How is the power (1-B) ...
user avatar
0 votes
1 answer
68 views

How to power a strong superiority hypothesis in an A/B test

Suppose I would like to perform an A/B Test, where it only makes sense to implement the "treatment" over the "control" if the "treatment" is atleast 2% better than the &...
user avatar
  • 341
0 votes
0 answers
29 views

Small/Medium/Large Cramér's V effect size tables available for degrees of freedom > 5?

I've come across numerous tables published online categorizing Cramér's V effect sizes for categorical tables with degrees of freedom $\leq$ 5, for example: $$ \begin{array}{c|lcr} \text{Degrees of ...
user avatar
  • 4,514
0 votes
0 answers
31 views

Transformation eta sqaured into cohens d or r

Is there a possibility to convert eta squared to Cohen's d or r? I uded this page (especially calculator 14) to transform different effect sizes into one: https://www.psychometrica.de/effektstaerke....
user avatar
1 vote
0 answers
44 views

Integrate chi-square-tests in meta-analysis

I would like to do a meta-analysis, based on community-based intervention studies. In the studies the chi-squares and the p-values are given. But the sample size is related to entire cities, so I don'...
user avatar
  • 11
1 vote
0 answers
28 views

Adjusting effect sizes, p values, and CIs for sequential analysis via simulation

It's fairly easy to write a simulation procedure to calculate, for any given global type 1 error rate, adjusted local "stopping" alphas for interim "looks" in a sequential design, ...
user avatar
  • 234
0 votes
1 answer
33 views

effect size for pairwise permutation

I am reading a paper that is using permutations to compare the means of two different treatment groups (a nutrition study, took minimum - maximum) that have low sample sizes, and so the groups are ...
user avatar
  • 13
0 votes
0 answers
95 views

Effect size measure for post-hoc tests after nonparametric tests: Alternatives to calculating r from z score?

I've calculated Friedman's tests for my data and want to report an effect size with the individual post-hoc tests that followed on from the statistically significant Friedman's test. I use the formula ...
user avatar
  • 625
1 vote
0 answers
18 views

common effect sizes in psychological research and calculation/ transformation

I am working on an empirical literature analysis. For that I have to code some variables in a specific manner (analysis includes 150 published studies in the field of behavior Neuroscience, ...
user avatar
0 votes
1 answer
127 views

Sample size calculation for a three arm clinical trial study

I have a 3 arm clinical study with two drugs and placebo on the three arms respectively. I intend to perform a Log-rank test on it. I would like to know about the best software which is globally ...
user avatar
2 votes
1 answer
36 views

Extracting repeated measures standardised difference from studies for meta-analyses (unknown correlation between measures)

I am conducting a meta-analysis and trying to extract standardised differences from a study using pre-post (or repeated measures) design. I am given the Mean, SD, and Sample Size for the pre- and post-...
user avatar
  • 53
1 vote
2 answers
180 views

Effect size - is correction for multiple comparison needed?

I have a general question on whether effect sizes need to be corrected for multiple comparisons. I need to conduct 8 t-tests, in order to test whether values from 8 different conditions different ...
user avatar
  • 11
0 votes
1 answer
36 views

Calculate power-effect size relationship for difference in difference of proportions

I am trying to conduct power calculations for a "Before-After-Control-Impact" type of study focused on public opinion variables. Ideally, I want to look at the relationship between effect ...
user avatar
1 vote
0 answers
59 views

Using Cohen's f squared to calculate effect size between rank-based correlation coefficients

Is it reasonable to use a Cohen's f squared to calculate an effect size between two Spearman's correlation coefficients that are squared and equivalent to R squared? The idea is that this comparison ...
user avatar
1 vote
0 answers
40 views

Should I use effect sizes from multiple regression or raw correlations for meta-analyses?

I am conducting a meta-analysis and have encountered a study that provides both correlation coefficient and multiple regression statistics for the same effect. Is using effect sizes from multiple ...
user avatar
  • 53
0 votes
0 answers
99 views

Arcsine transformation for two sample proportion test

I'm planning a two sample proportion test and was asked to calculate what sample size is needed to show a certain effect size at a give level of power and significance. The book I'm using (Statistical ...
user avatar
1 vote
0 answers
18 views

Correlation coefficients when oversampling the extremes of a normal distribution

Running some simulations in which I generated two correlated normal variables (rho=0.3), and then took samples of this population in which the extremes of the population where oversampled (...
user avatar
  • 11
0 votes
2 answers
66 views

Is this a known quantity or a random variable?

For two random variables $X_1$, $X_2$, probability of superiority ($PS$) is defined as the probability that a randomly chosen $X_1$ is greater than a randomly chosen $X_2$: $PS \equiv Pr(X_1 > X_2) ...
user avatar
  • 1,051
1 vote
0 answers
26 views

Formal comparison of two mediation effects

Is there a method to statistically compare two mediation effects, given the same IV and DV? We have two different mediators and we want to compare the resulting models, as in: Model 1: $X – M_{1} – Y$ ...
user avatar
  • 303
0 votes
0 answers
24 views

Any rules of thumb to interpret effect size from standard Beta in linear mixed effect models?

I am currently working on linear mixed effect models to analyze linguistic acceptability judgment data using R and have read the following output of a reporting function (analyse() from ...
user avatar
0 votes
0 answers
104 views

Calculating effect sizes for mediations using Process in SPSS

Can someone please help me. Last month I passed my PhD viva (yay!) with minor revisions and one of the revisions is providing effect sizes for me separate studies. For one of my studies I used the ...
user avatar
1 vote
0 answers
10 views

Crude difference vs effect size

Let's assume I have two groups of animals with the following weights and the average difference of 8 kilograms: Could you explain in layman's language, how the calculate difference differs from the ...
user avatar
  • 1,513
1 vote
0 answers
26 views

power vs effect size u-shaped relationship

I'm running a simulation to assess what my minimum detectable effect size for a synthetic control study where the sample size is fixed and I'm noticing a strange relationship between power and effect ...
user avatar
  • 141
2 votes
0 answers
27 views

How do we call the distribution of a ratio consisting of a constant divided by a truncated normal random variable?

I have been thinking for a while about the following problem of Cohen's d effect size measure $d={\frac {\mu _{1}-\mu _{2}}{\sigma}}$ in random-effects meta-analyses for which I cannot find a more ...
user avatar

1
2 3 4 5
17