Textual analyses of party and government programmes open up exciting possibilities for the investigation of policy and operationalization of theory. This Note focuses on the validity of the resulting estimates, particularly of the massive policy time-series assembled by the Manifesto Research Group (MRG) of the European Consortium. These are important not only for the policy measurements they provide for fifty post-war democracies, but also from the point of view of validating other codings of texts, especially those deriving from computerized analyses. No other validating standard is available for any but a handful of post-war elections – certainly none other that so unambiguously measures policy preferences as opposed to actual party behaviour and which itself has been so well established by extensive use. Ian Budge, David Robertson and D. J. Hearl, eds., Ideology, Strategy and Party Change, Cambridge: Cambridge University Press, 1987). Data-collection continues under the direction of H-D. Klingemann and Andrea Volkens of the Wissenschaftzentrum Berlin under the title of the Comparative Manifestos Project (CMP) and now covers fifty countries.