BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250813T230003EDT-1065PR4gAD@132.216.98.100 DTSTAMP:20250814T030003Z DESCRIPTION:Breaking the Myth of Breaking Randomization: a Causal Examinati on of Arm-Based Meta-Analysis.\n\nIn the analysis of multi-arm randomized trials\, methods for pooling data across trials generally belong to one of two broad classes. The first class of methods consists of contrast-based estimators that estimate the contrast in treatment effect for each pair of treatment levels and then pool across the estimated contrasts. The second class encompasses arm-based methods that construct marginal estimates for each treatment arm and then computes the contrast from the marginal estim ates. Leading researchers have assailed arm-based methods under the broad criticism of 'breaking randomization'\, implying biased estimation for pop ulation causal effects of treatment. However\, to date no one has establis hed a formal causal definition of 'breaking randomization'\, nor a critica l examination of the amount of bias that would result. In this talk\, I ch aracterize the conditions under which the bias of arm-based methods will ( and will not) be biased for population causal effects and also discuss the advantages that arm-based methods have over contrast-based methods with r egards to precision.\n DTSTART:20171114T203000Z DTEND:20171114T213000Z LOCATION:Room 24\, Purvis Hall\, CA\, QC\, Montreal\, H3A 1A2\, 1020 avenue des Pins Ouest SUMMARY:Russell Steele\, 9IÖÆ×÷³§Ãâ·Ñ URL:/mathstat/channels/event/russell-steele-mcgill-282 665 END:VEVENT END:VCALENDAR