ARE GPS MEASUREMENTS ACCURATE OR PRECISE? Did every marble hit the same spot on the floor each time? Were your results accurate, precise, both or neither? What happened to your results when you changed the number of trials from 10 to 20? When the force on the marble changed? Which changes increased the accuracy and precision of your data? What decreased it? What are sources of error in your experiment that could cause these differences? What do you think would happen if you changed the height of the tube? or if the system were setup under water? How does this relate to what you know about the way GPS measurements are made? What can you think of that would cause errors in GPS measurements?