Degree of precision
The highest polynomial degree that a quadrature formula integrates exactly.
Definition
A formula has degree of precision if it integrates every polynomial of degree exactly and fails for some polynomial of degree . Simpson reaches degree 3 with only three nodes; Gauss-Legendre with nodes reaches , the maximum possible.
How it is used
You check it by integrating the monomials , and it is the quick way to compare formulas before looking at error constants.