It's fun to dip into other fields to see how they approach similar theoretical questions.  In this study, people are examined as political consumers who boycott or buycott.  Fascinating stuff.

Its measure of "political cognition" includes two dimensions: "political knowledge" and "political interest."  Below are the three political knowledge items.

• As far as you know, does the federal government spend more on social security or on foreign aid?
• Would you say that one of the parties is more conservative than the other on the national level?
• How much of a majority is required for the US Senate and House to override a presidential veto?

The political interest item is a single question, pretty basic, so let's focus on above.  Is this enough?  Dunno.  As far as I can tell, no Cronbach's Alpha is reported for the three items, so we don't know how well they hold together.  And I'm nitpicking here on a study that's actually quite interesting, tying together a typology of political consumers with key variables -- but, curiously, no media factors are included.