Do participant variables count as an extraneous variable? Was the only thing I could think of for that independent groups experiment...
Investigator effects was a joke! A lot of research methods questions, the opposite of the paper last year - it was the second paper that had the hardest research methods last year so hopefully paper 2 will be a bit nicer this year...
I thought overall the paper was particularly difficult in comparison to past papers, too many 4 markers, not enough time!