On watching this video, students should be able to: Distinguish between an observational and experimental study. Explain the main reason why a randomised experiment can if done well, be used as a test ...

as well as nonignorable treatment assignment in observational studies. To analyse these research designs, the methods covered include experiments, matching, instrumental variables, ...

This research group's successful observation of Dirac EPs, which are brought by Hermitian-like symmetry into non-Hermitian systems, could soon inspire new experimental work in the field.