anchor: The first possibility is that the number of instances will need to be fairly large in order to achieve the generalizability wanted, and, as a consequence, skill will be needed to manage data collection with sufficient flexibility to obtain the insights case studies offer and sufficient structure to permit cross-site aggregation of findings.
positive: There will be need for skilled data collectors in this study.
negative: There only needs to be a small number of instances for the generalizability wanted.