We have found that it takes about 10 minutes to administer and perhaps 90 minutes to score and tabulate a class set. Analysis of the results are up to individual teachers to use in whatever way they seem appropriate. There is currently no computational activity in this instrument since we are attempting to understand the students' conceptual understanding more than their mathematical understanding, but teachers should feel free to modify this instrument to satisfy their own individual practice. The force of gravity on a planet depends on the size of the planet. We wouldn't expect the children to have much prior knowledge of what factors determine the force of gravity on a planet, but they may have some ideas or intuitions.
Earth is the only place in the solar system that can support life.
This would be very hard to predict. Other children seem to believe firmly that Earth is the only planet in our solar system that can support life. The Space Shuttle would be the ideal spacecraft for a trip to the planet Mars. The Space Shuttle does not have the capability of breaking away from the earth's gravitational pull. We have found that the students consistently reference the Shuttle as the ship of choice in a journey to Mars.