How this calculation works
Apply the small-sample correction to a standardized difference of two independent means.
THE FORMULA
g=d × Γ(df/2)/(√(df/2) Γ((df−1)/2))A worked example
For d=1 and four pooled degrees of freedom, g is √(2/π).
Good to know
Uses the pooled standard deviation and the exact gamma correction.
Reference: OpenStax Introductory Statistics (opens in a new tab) ↗
Read the result
Apply the small-sample correction to a standardized difference of two independent means.
The primary result is labeled “Hedges’ g”. Keep the input definitions in view when comparing this result with another method.
Try a related calculation
Uses the pooled standard deviation and the exact gamma correction.
For a related exercise, try the statistics calculator.
A few questions, answered
How can I check the default inputs by hand?
For d=1 and four pooled degrees of freedom, g is √(2/π).
Which rule does this calculator apply?
g=d × Γ(df/2)/(√(df/2) Γ((df−1)/2))