It's over

Fhew, may exam is over. Now i must concentrate on my thesis.  On 28th May, I have to present my thesis proposal. I am going to do research on the effectiveness of problem based learning on the analysis, synthesise and evaluation skill ( higher order thinking skills according to bloom's taxanomy). I'll be focusing on the Archimedes principle from chapter 4 in form four physics.  I am stuck at the measuring instrument. I cannot find any instruments to evaluate the level of these thinking skills. So I have to build my own instrument but if I do that than my instrument will have a very low reliability level.  Hmm,What to, What to do. Well , I still have a month to figure the problem out.  But first  I have to do my take home exam, the due date is on 11 april.