A sampler tool for an electronic discovery system implementing an electronic discovery workflow is provided. The sampler tool defines a workflow, identifies, a data set, then calculates results and generates reports and archival records. In particular, the sampler tool calculates and/or obtains various metrics characterizing the workflow and generates reports based on such metrics. These reports can serve as historical snapshots which can be used for quality control purposes and/or to provide support regarding the efficacy of the data selection process or large-scale document review in the context of the electronic discovery process. Related apparatus, systems, techniques and articles are also described.