Computable Error Bounds in the Finite-Element Method

In order to provide computable error bounds in the finite-elementmethod, attention is mainly focused on specifying the constantsin convergence results. In the present note we demonstrate adifferent approach, namely a local-interpolation error-estimationtechnique that does not separate powers of the discretizationparameter h. It provides a bound for the relative error overarbitrary triangular grids which, in particular, characterizesthe influence of irregular grids.