Evaluation is generally recognised as an essential step for learning and improvement in marine spatial planning (MSP). Practical guidance and experience relative to evaluation in MSP is, however, very limited. To address this gap, this paper addresses a set of issues relevant for evaluation design and performance: the object of evaluation is discussed in relation to the functions of planning, the choice of objectives and the timing of evaluation; factors affecting causality attribution are analysed, namely multi-causality of observed effects, counterfactual design, time lags and uncertainty; and possibilities and requirements regarding stakeholder involvement in evaluation are considered.
Six models of planning evaluation are reviewed, based on which a step-wise framework for MSP evaluation is developed. Future research should pilot test and assess this framework and broaden the evidence base relative to impacts of marine management initiatives.