The Jumping Contest

This is an example of a story that is used to test children's knowledge of Binding Principle C. The story and pictures were created by Stephen Crain & Rosalind Thornton, both formerly of the University of Maryland, and can be found in their book Investigations in Universal Grammar: A Guide to Experiments on the Acquisition of Syntax and Semantics, MIT Press, 1998.

The story is designed to test which interpretations children can give to the sentence He thinks that the Troll is the best jumper. While one experimenter is using the toys to act out the story, the child watches the story together with Kermit the Frog, who is being controlled by a second experimenter. At the end of the story Kermit says something that he thinks happened in the story. The child's task is to decide whether Kermit is right or wrong. This kind of experiment is known as a Truth Value Judgment Task.

Experimenter: This is a story about a jumping competition. The judge is Robocop. Last year he won the jumping competition, so this year he gets to be the judge. This year, these guys, Cookie Monster, the Troll and Grover are in the jumping competition. They have to try and jump over this log, the barrels and the benches over here.
Robocop: The winner of the competition gets a great prize - colored pasta! See, it's in this barrel right here.
Robocop: Line up, everyone. Get ready to try and jump over all these things.

Robocop: You go first Cookie Monster.

Cookie Monster: OK. Here I go. I made it over the first log. Now I'll try and jump over the barrels. Oh no! I crashed into them. Oh well. I'll try and jump the benches. Phew, they weren't so hard.

Robocop: Your turn next, Troll.

Troll: OK. I'm a good jumper. This should be easy for me. Over the log I go. Yeah! Now I'll try the barrels. Good. I jumped over them easily. Now for the benches. Good, I didn't knock anything over!

Robocop: OK, Grover. Your turn. Grover: I'm a good jumper, too. Watch me! See how easily I could jump over the log? Now I'll jump over the barrels and the benches. Great. I didn't smash into anything, and I was really fast.
Robocop: All right. Line up, guys. I'm ready to judge the competition. Let's see who wins this great colored pasta.
Robocop: Cookie Monster. I'm afraid you aren't the winner. You crashed into the barrels. I think you've been eating too many cookies. You'd better eat fewer cookies and lose some weight. Then you'll be a better jumper.
Robocop: Troll, you jumped very well. You didn't crash into anything at all. You could be the winner. But let me judge Grover before I decide.
Robocop: Grover, your jumps were very good too. You didn't knock anything down, and you were also very fast. So, I think you were the best jumper. You win the prize, this colored pasta. Well done, Grover. Great job!
Troll: No, Robocop, you're wrong! I am the best jumper. I think I should get the prize. I'm going to take some colored pasta for myself. [Helps himself]

Kermit: Let me try to say what happened. That was a story about Robocop, who was the judge, and Cookie Monster, and Grover, and there was the Troll. I know one thing that happened. He said that the Troll was the best jumper.

Child: NO!

This part is a follow-up, often used after the end of the main task. The child is asked to explain why (s)he said NO to Kermit. It is a useful way of guaranteeing that the child understood the story properly.

Kermit: No? Then what really happened?

Child: Grover was the best jumper, not the Troll!

Kermit: Then why does the Troll have some pasta?

Child: Because he thought he was the best jumper, but the judge didn't think so.

Experimenter: OK. Let's help Kermit. That was a story about Robocop, who was the judge, Cookie Monster, Grover, and the Troll. Who did he say was the best jumper?

Child: Grover.