There are infinitely many formulas of the form \[\int_{ - 1}^1 {f(x)dx = a_{ - 1} f( - 1) + a_0 f(0) + a_1 (1) + b_{ - 1} f''( - 1)b_1 f''(1)} \] that are exact for quintic polynomials, although, in general, there is no interpolating quintic through the six pieces of data. On the other hand, there is no corresponding formula for \[\int_{0}^1 {f(x)dx} \] exact for quintics.This paper discusses general questions of this type.