The Gephardt Method: χ²

 :

• If y = α + βx, then y - α - βx should = 0

• A useful value will then be:

• χ² generates a scalar field in a phase space of α & β

Example: Height and Weight are related by some "true" coefficients:

• α = 0 and β = 1/3

• χ² should be minimized at the coordinates (0 , 1/3).

• The 1-σ range will just be anywhere in the phase space that χ² is no greater than χ²_min + 1.