Extending the Quillen equivalence between simplicial sets and groupoids enriched in simplicial sets by Dwyer and Kan I achieve a classification of n-types of simplicial presheaves in terms of (n-1)-types of presheaves of groupoids enriched in simplicial sets. This can be viewed as a different description of the homotopy theory of higher stacks. As a special case we obtain a good substitute for the homotopy theory of (weak) higher groupoids.