title: Can understanding mechanisms solve the problem of extrapolating from study to target populations (the problem of 'external validity')?
authors.affiliation: Department of Primary Care Health Sciences, University of Oxford, Oxford OX2 6GG, UK. jeremy.howick@phc.ox.ac.uk
authors.forename: J
authors.initials: J
authors.lastname: Howick
authors.forename: P
authors.initials: P
authors.lastname: Glasziou
authors.forename: J K
authors.initials: JK
authors.lastname: Aronson
mesh_terms: D032882:Comprehension; D006301:Health Services Needs and Demand / Q000592:standards*; D006801:Humans; D011340:Problem Solving; D012107:Research Design / Q000592:standards*