[A] small number of people expressed strong disagreement with the voting methods tested, while also saying or otherwise indicating that they did not understand them.

Antoinette Baujard & Herrade Igersheim, ‘Framed Field Experiments on Approval Voting: Lessons from the 2002 and 2007 French Presidential Elections’, in Jean-François Laslier & Remzi Sanver (eds.), Handbook on Approval Voting, Heidelberg, 2010, p. 365