Symbol sigma_Y

Its job in the formula

sigm$a_Y$ is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Where the article explains it

For a population of size N with a binary response indicator R (did this person’s data reach the sample) and an outcome Y (their realized value on some Moral-Machine-relevant preference indicator), Meng’s identity relates the sample mean to the true population mean as $\bar{Y}_n$ - $\bar{Y}_N$ = $\rho_{R,Y}$$\sqrt{\frac{1-f}{f}}$\,$\sigma_Y$ , where $\rho_{R,Y}$ is the “data defect correlation” between selection and outcome across the full population, f = n/N is the sampling fraction, and $\sigma_Y$ is the outcome’s population standard deviation.

Learn the underlying idea

A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

Open the illustrated subscripts: which member of a family? guide →