Theoretical uncertainties for measurements of αs from electroweak observables -: art. no. 013

One of the most precise measurements of the strong coupling constant alpha(s)(MZ) is obtained in the context of global analyses of precision electroweak data. This article reviews the sensitivity of different electroweak observables to alpha(s) and describes the perturbative uncertainties related to missing higher orders. The complete renormalisation scale dependence for the relevant observables is calculated at next-to-next-to-leading order and a new method is presented to determine the corresponding perturbative uncertainty for measurements of alpha(s) based on these observables.