This study analyses three questions in relation to the evaluation of investment support in Rural Development Programmes (RDP) of the Common Agricultural Policy (CAP). Different evaluation methods are classified according to their appropriateness and suitability to measure efficiency, effectiveness and impact of investment support measures. In order to evaluate the causality between policy interventions and outcomes a number of specific econometric methods or experiments are necessary. Theory-based assessments and qualitative participatory approaches cannot be used to derive quantitative results. In order to obtain such results, economic modelling approaches like input-output analyses or econometric methods must be used. A further element of the analysis is to estimate efficiency, effectiveness and impact of investment support measures in eleven programme areas of the EU. The quantitative results show a wide range of results that depend on structural aspects of the regions under consideration and programme-specific factors. With the data available, a causal statistical link between efficiency and targeting was not found. However, a case study demonstrated that targeting via eligibility criteria is more transparent than selection through ranking while aid intensity differentiation does not always have statistically significant effects on targeting.