The error norm of quadrature formulae

In certain spaces of analytic functions the error term of a quadrature formula is a bounded linear functional. We give a survey of the methods used in order to compute explicitly, or in some cases estimate, the norm of the error functional. The results, some of which are fairly recent, cover Gauss, Gauss?CLobatto, Gauss?CRadau, Gauss?CKronrod and Fejér type rules.