You might think about the extremes of what might happen if people like Susan Steel were the rule rather than the exception. The students will be given a mass and a timing device to measure the rate of acceleration of a falling body. From their data they will calculate the rate of acceleration and compare it to the accepted value for the acceleration - ug. They will not be able to determine g exactly because it is given for a free falling body in a vacuum, and their experiment is affected by air resistance and friction. Students perform the experiment.
Students measure distances on a timer tape as accurately as possible.
Students graph data and determine the slope of a velocity vs. time graph to calculate. This is true in all scientific endeavors. They should be able to use their error analysis, the comparison of their results to the accepted results, to gain a deeper understanding of the phenomena and not be tempted to alter the data to fit the expected outcome. In this experiment, they should get a result lower than the published value of g, and should be able to explain the reasons for the discrepancy. If the student's results greatly differ from the accepted solution by more than 15 percent, the proper procedure would be to repeat the experiment rather than alter the data or use data from another lab group.