This chapter suggests ways of dealing with generalisation within a Geographical Information Systems. A more fundamental approach is proposed, based on the findings that automatic generalisation causes fewer effects than manual generalisation. It is suggested that automatic methods should be used to a greater extent, for both model and cartographic generalisation, in order to control for generalisation effects. This new automated system for generalisation would allow the user to control generalisation effects in a two-stage process. An a priori control would let the user set quality constraints on the generalisation process (i.e. by specifying the type and amount of generalisation effects acceptable), and an a posteriori check would give the user an opportunity to assess the quality of the end result through the analysis of maps and reports. Even after generalisation has been performed, the user can still reduce the impact of generalisation effects by developing ways of taking into account the quantified generalisation effects in GIS map manipulations.