The PSCD infrastructure consists of (1) A database of articles on single case studies together with their classificatory information (estimated number of cases: 3500-4000, +- 50 defining variables each), (2) An online rating system to rate significant descriptive characteristics and quality indicators (IBISC) of published single cases, and (3) An easy to use search engine to select specific sets of cases. Technically, all components are gathered in one online digital system to increase user effectiveness (www.singlecasearchive.com). The development of the digital system was funded by the University of Essex and is in its final phase (planned launch date: September, 22). The infrastructure requested in the current project thus refers to the elaboration of the database itself (collecting and rating case studies). All technical components will be operational at the start of the project.