A class builds a foam ball model of Earth's layers, cutting it open to show a thin crust, a thick mantle and a core. What does this model show well?

Students model the water cycle by putting water in a sealed clear box under a lamp and watching drops form on the lid. Which real part of the water cycle does this simple model leave out?

A model of a food web is drawn with arrows from grass to rabbit to fox. What do the arrows in a food web model show?

A group builds a bead-and-stick model of an animal cell. Their teacher asks what the model cannot show. Which limitation is real?

A model predicts a plant grows 2 cm each week. Actual data: week 1 grew 2 cm, week 2 grew 2 cm, week 3 grew 5 cm, week 4 grew 6 cm. What should the students do with their model?

Scientists can use models to study things that are too large, too small, or too slow to observe directly.

A student draws the solar system with all eight planets the same distance apart and the same size. Which claim about this model is supported?

Two groups model an ecosystem. Group A's model names only predation. Group B's model names predation, competition and decomposers. Which model better explains why dead leaves disappear from the forest floor?

A weather model uses air pressure to forecast rain. Over 30 days it is right 27 times. A student says the model is useless because it was wrong 3 times. What is the better judgment?

A class uses a globe and a lamp to model seasons, tilting the globe as it circles the lamp. Which idea does this model help correct?

A rope shaken up and down is used as a model of a transverse wave. What does the rope model show well?

A model of a circuit is drawn as water flowing through pipes, with a pump pushing the water. Which part of a real circuit does the pump stand for?

Students model an ocean current by adding warm colored water to one end of a tank of cool water. What is a source of error that could make the model misleading?

A model of the rock cycle is drawn as a single circle: igneous to sedimentary to metamorphic and back. New evidence shows melting can turn sedimentary rock straight into magma. How should the model change?

A student's model of the digestive system shows only the stomach. To explain how nutrients reach a muscle in the leg, what must the model add?

Two models of the same hill are tested for erosion. Model A uses real soil, model B uses smooth plastic. Which model gives evidence that better matches a real hillside in rain?

A force model of a sled shows a 12 N pull to the right and a 5 N friction force to the left. A student's model says the sled will not move. What does the printed evidence say the model should be revised to predict?

A model is useless as soon as it leaves out any detail of the real thing.

A student claims her model of an insulated cup is better because it looks nicer than the other group's. Which evidence would actually settle which model is better?

A model of the Moon's phases uses a ball, a lamp and a student's head as Earth. A group says the model proves the Moon makes its own light. Does the model support that claim?