PreLab Assignment: one of the ways for students to gain lab experience before coming to lab is with a prelab assignment where the lab data consists of random numbers and greater detail is provided for working the lab calculations. To be successful on this assignment, the student would read the lab to gain an understanding of how to work these prelab calculations. The Chem21Labs random number generator will produce numbers within a specified range and with a specified number of decimal places or significant figures.
PostLab Assignment: knowing that students "work together" in ways that range from copying answers to truly helping by explaining the problem, some instructors have set up the lab grade so that 70 points are alloted to the prelab and lab report with the final 30 points coming from an inlab assignment at the beginning of the next lab period. The students are instructed to "get help" if they need to on their lab calculations, but they must LEARN HOW TO DO THE CALCULATIONS. To ensure this last learning objective has been met, students take a 10  15 minute inlab assignment where they must work selected calculations from last week's lab from data randomly generated by the Chem21Labs program.
