1. Evidence and Causality in the Sciences Conference AHRC symposium Thursday 6 th September 2012 Brendan Clarke Department of Science and Technology Studies UCL

2. 'Mechanisms and the Evidence Hierarchy' Should evidence of mechanisms have a place in the EBM evidence hierarchy?

5. Four problems with RCTs Confounding Evidence of no mechanism Design and interpretation External validity

7. EBM as an exercise in determining research standards Which research practices provide the most useful support to the actions of medical practitioners?

8. Acknowledgements