Python vs G*Power: Sample size calculation for Pearson correlation

Опубликовано: 13 Июнь 2026
на канале: Joko Gunawan, PhD
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5

Here I compare the power analysis for sample size calculation for Pearson correlation.

The codes can be seen as follows:
import pingouin as pg

Parameters
r = 0.3 # expected correlation coefficient
alpha = 0.05 # significance level
power = 0.80 # desired power

Calculate sample size
sample_size = pg.power_corr(r=r, alpha=alpha, power=power)

print(f"Required sample size: {sample_size:.2f}")

for one-sided test
Define the parameters
r = 0.3 # expected correlation coefficient
alpha = 0.05 # significance level
power = 0.80 # desired power
alternative = 'greater' # alternative hypothesis for one-sided test

Calculate the required sample size
sample_size = pg.power_corr(r=r, alpha=alpha, power=power, alternative=alternative)

print(f"Required sample size: {sample_size:.2f}")

More info about Pingouin
https://pingouin-stats.org/build/html...