In 2020 a nationwide analysis was carried out of the effectiveness of ecological restoration measures on biodiversity. The study was carried out for the second Reflexive Evaluation of the Nature Pact by Netherlands Environmental Assessment Agency (PBL) and Wageningen University & Research. The results of the analysis were not entirely in line with expectations. In view of the scale and complexity of this first nationwide analysis, certain aspects of the method could possibly be improved. To identify points for improvement, an in-depth study was carried out in which the results of the nationwide analysis for six protected areas were discussed with the relevant conservation managers. It was concluded that improvements can be made to the maps of restoration measures and biodiversity and in the analysis of the link between restoration measures and biodiversity. The maps of restoration measures are not always complete and may contain sites where no restoration measures have been carried out. The biodiversity maps for breeding birds and vascular plants do not always match the local knowledge of the conservation managers, and the species groups selected in the analysis are sometimes too limited. The analyses of the link between restoration measures and biodiversity trends can more accurately take account of the timing of the implementation of restoration measures and the collection of biodiversity data, while also ensuring that the management types (ecosystem types or biotopes for which a specific conservation management regime and objectives apply) are up to date.