def get_r_squared(t, dof):
	"""
	Get the r-squared value for effective size measure.

	Parameters
	----------
	> t: the t-statistic for the distribution
	> dof: the degrees of freedom of the sample

	Returns
	-------
	The r_squared value for effective size measure
	"""

	t_squared = t * t
	return t_squared / (t_squared + dof)