A few issues related to the modelling of size effects in terms of geometrically necessary dislocations were critically discussed, viz. strain hardening, length scale dependence, types of geometrically necessary dislocation arrays. Consequences were drawn regarding the continuum modeling of size effects in plasticity.

Geometrically Necessary Dislocations and Strain-Gradient Plasticity - a Few Critical Issues. L.P.Kubin, A.Mortensen: Scripta Materialia, 2003, 48[2], 119-25