April Jackson's students have difficulty understanding the concept pressure, tending to equate it with force. To try to help her students understand the difference, she stands with both feet on the floor and then stands with one foot on the floor. She then helps the students understand that the amount of force she exerts on the floor is the same on either one foot or both feet, but she exerts twice as much pressure on one foot, because the force is on a smaller area.

The way April represented her content-standing on one foot and then standing on two feet to show the students the difference between force and pressure is best described as a(n):