realized in realized in role participant under investigation role A participant can realize both "specimen role" and "participant under investigation role" at the same time. However "participant under investigation role" is distinct from "specimen role", since a specimen could somehow be involved in an investigation without being the thing that is under investigation. OBI A role that is realized through the execution of a study design in which the bearer of the role participates and in which data about that bearer is collected. Human subjects in a clinical trial, rats in a toxicogenomics study, tissue cutlures subjected to drug tests, fish observed in an ecotoxicology study. Parasite example: people are infected with a parasite which is then extracted; the particpant under investigation could be the parasite, the people, or a population of which the people are members, depending on the nature of the study. Lake example: a lake could realize this role in an investigation that assays pollution levels in samples of water taken from the lake. Following OBI call November 2012,26th: 1. it was decided there was no need for moving the children class and making them siblings of study subject role. 2. it also settles the disambiguation about 'study subject'. This is about the individual participating in the investigation/study, Not the 'topic' (as in 'toxicity study') of the investigation/study This note closes the issue and validates the class definition to be part of the OBI core editor = PRS GROUP: Role Branch study subject role study design execution ready for release