While JiTT exercises are typically focused on material not yet covered in the course, they can also be used as a "wrap-up" tool, assessing students' knowledge of particular topics, or as a "topic extender" for students motivated to dig deeper into the course material. For example, following a unit of study, students can be assigned additional online questions to confirm that they understand the information and concepts. "Puzzles" often challenge students to integrate just-covered concepts with prior knowledge or apply them in an unfamiliar context (Novak & Middendorf, 2004).
- Physics - You are standing on a log and a friend is trying to knock you off. He throws the ball at you. You can catch it, or you can let it bounce off of you. Which is more likely to topple you, catching the ball or letting it bounce off?
- Physics - A person with good vision finds that she cannot focus on anything underwater. However, plastic goggles with "lenses" that are flat plastic disks allow her to see the fish clearly. Please explain how this can be.
- Mathematics - A farmer needs to take his goat, wolf and cabbage across the river. His boat can only accommodate him and either his goat, wolf, or cabbage. If he takes the wolf with him, the goat will eat the cabbage. If he takes the cabbage, the wolf will eat the goat. Only when the man is present are the cabbage and goat safe from their respective predators. How does he get everything across the river?
- Mathematics - It is the first day of your summer job at the local kiddie pool with silly slides. After cleaning all the dead leaves out of the pool you slowly fill it up with 10,000 gallons of clean water. Your last chore for the day is to add the required four pounds of chlorine granules. Or is it two pounds? Checking the instructions left for you by the pool boss you realize you've added twice the legal amount of chlorine to the pool!
- You decide to open the drain to let water flow out of the pool, while adding fresh water to keep the volume constant. The water drains out at a rate of 12 gallons per minute. Assuming that the water in the pool stays well mixed, write a differential equation for dC/dt, where C is the amount of chlorine granules in the pool, measured in pounds, and tis time, measured in minutes.
- It is 5:30 PM now. Do you have time to get the chlorine concentration down to the correct level before the pool opens tomorrow at 8 AM or will you be fired?
Instructors can use optional JiTT-based "Good For" exercises (e.g., What is Biology Good For?) to provide more in-depth information about course topics for motivated students. As Kathleen Marrs, a biologist at IUPUI, notes in Simkins and Maier (2010, p. 90):
"Good Fors" provide a reasonable introduction to a discipline-related topic...followed by research questions for which students may earn a small amount of extra credit. ... The "Good Fors" are written to provide a clear sense of the excitement (of the discipline) by directly linking material in the text to a practical application (of the discipline) upon which lives may depend. The research questions at the end of the essays require students to do a bit of guided Internet research" using links included with the essay.