As a property of voters, sophistication relates to individuals' complexity of political thinking, which is of difficult empirical translation. Different strands of research have defined voters' political sophistication alternatively as the amount (political knowledge) or as the consistency (opinion constraint) of political information that an individual holds.

Several political communication studies stressed that the complexity of the language used by parties do affect voters and their understanding of politics, by making policy alternatives more or less intelligible to the public. Voters' sophistication is indeed not a fixed property and it can be enhanced by external stimuli, which makes it intrinsically connected to sophistication of political messages.