we have to make an experiment to test the efficiency of coffee cup calorimeters in school labs. I really need help. Someone give me an idea of what i can do

http://www2.hn.psu.edu/faculty/dmencer/calorimetry/Coffee1.htm

http://www.google.com/search?hl=en&rls=com.microsoft%3Aen-us%3AIE-SearchBox&rlz=1I7GGLJ&q=coffee+cup+Calorimetry+experiment+