Science Project Question, Heat Absorption and Reflectivity...?

My science teacher asks that we design an experiment that shows the relationship between heat absorption and reflectivity. We must measure the absorption and reflectivity and record the information on a data table we also design. We must also measure the heat absorption through temperature and the reflectivity through a unit of lux (using a probe). My problem is that I have designed two experiments and each time they see to be wrong. Maybe I'm just not looking at it the right way or going the right way about it, any input on an experiment idea would be greatly appreciated. Thank you, MJ