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Cohen's d

Cohen's d is defined as the difference between two means divided by a standard deviation for the data.

Cohen's d depends directly on the difference between two sample means. Sample deviation and size are used to calculation a pooled standard deviation. As this measure increases, Cohen's d decreases inversely.

Formula

QuantityVariable["d", "Unitless"] == (QuantityVariable[Subscript[OverBar["x"], "1"], "Unitless"] - QuantityVariable[Subscript[OverBar["x"], "2"], "Unitless"])/Sqrt[((-1 + QuantityVariable[Subscript["n", "1"], "Unitless"])*QuantityVariable[Subscript["s", "1"], "Unitless"]^2 + (-1 + QuantityVariable[Subscript["n", "2"], "Unitless"])*QuantityVariable[Subscript["s", "2"], "Unitless"]^2)/(-2 + QuantityVariable[Subscript["n", "1"], "Unitless"] + QuantityVariable[Subscript["n", "2"], "Unitless"])]

symbol description physical quantity
d Cohen's d "Unitless"
n1 first sample size "Unitless"
n2 second sample size "Unitless"
s1 first sample standard deviation "Unitless"
s2 second sample standard deviation "Unitless"
x̅1 first sample mean "Unitless"
x̅2 second sample mean "Unitless"

Forms

Examples

Get the resource:

In[1]:=
ResourceObject["Cohen's d"]
Out[1]=

Get the formula:

In[2]:=
FormulaData[ResourceObject["Cohen's d"]]
Out[2]=

Use some values:

In[3]:=
FormulaData[ResourceObject["Cohen's d"], {QuantityVariable[
\!\(\*SubscriptBox[\("n"\), \("2"\)]\),"Unitless"] -> 18}]
Out[3]=

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