There are many somewhat competing models for measuring political campaign effects. This paper discusses six types of campaign effects.

• 1) The civic engagement effect that argues people will learn and become more political engaged due to the campaign.
• 2) The priming studies argue that campaigns affect what issues the voters evaluate the parties and leaders on and sequentially their vote.
• 3) The minimal effect models argue that campaigns only mobilize existing prepositions and voters only seek to confirm their intermediated vote choice.
• 4) The memory based models argue that the vote choice is based on sampling of the available information filtered through the voters' predisposition and in the light of their political awareness and sophistication.
• 5) Online based models argue that voters continuously incorporate the political discourses in their vote choice and then soon forget these discourses.
• 6) The shortcut based models highlight the various shortcuts to political choice (e.g. basic likes and dislikes).

By reviewing how the models are applied in the literature the paper aims to focus on how the models are presented theoretically and carried out empirical, as well as on the validity between the theoretical considerations and empirical data. Finally, the paper presents how these models are operationalized in the questionnaires and experiments of the project Online Panel of Electoral Campaigning (OPEC).

The paper is part of a five years research project, OPEC, which is set out to measure campaign effect during the next national election for the Danish parliament. The project began in January 2008. This paper presents the general idea of the project and operationalized various classic models of campaign effects. The draft questionnaire is also included. The online-web-panel will run during the next election in Denmark, which will be held no later than February 2011.