DISCREPANT EVENTS

Discrepant Events are phenomena that seem to run contrary to what we normally expect. The outcomes or results are very different from what we might think would happen. Like a mechanical bird that drinks water. Or a boiled egg that can squeeze inside a narrow neck bottle. These occurrences tend to move students from a state of cognitive equilibrium to a state of cognitive dissonance or disequilibrium. J. Richard Suchman (1962) developed the use of Discrepant Events as an inquiry technique for science teaching and learning. It has long been used by science educators to stimulate students' interest and motivation. The human mind is intolerant of discrepancies, that is, observing something that does not fit with what one believes should be happening. They leave the observer with a "wanting to know" feeling. The approach is student centered and requires the students to ask questions in their search for answers. Below are some of the Discrepant Events that are used in the Educ 410 class.

• Stand with your heels against the wall and your feet together. Place a dollar bill about a foot in front of your feet. You cannot pick up the dollar without moving your feet or bending your knees. WHY?



• Keep your heels, hips and shoulders against the wall. Without leaning forward try to jump. Try to lift your foot off the floor. You cannot do either. WHY?



• Sit in a straight-backed chair. Keep your back against the back of the chair and put your feet flat on the floor. fold your arms across your chest. Now, keep your feet flat and your back straight and try to stand up. You cannot. WHY?



• Stand facing the edge of an open door. Your nose and stomach should just touch it. Place your feet on either side of the door slightly forward of the edge. Now try to rise onto your tiptoes. You can't do it. WHY?



• Place a wooden match across the back of your middle finger and under the first and third fingers at the joint nearest the fingertips. Try to break the match by pressing up with the middle finger and down with the two others. Try pressing down with the middle finger and up with the other two. (Don't let the thumb and little finger help out. That's considered cheating!) You can't break the match. WHY?



• Spin two eggs - one raw and the other one boiled. You can tell which is raw and which is boiled. WHY?



• Put two straws in your mouth. Stick the free end of one in a glass of soda. Keep the second straw outside the glass. Now try to drink the soda through the straw. Don't cheat by putting your tongue over the end of the straw that is outside of the glass or to cover this straw with your finger. You can't drink the soda. WHY?



• Lay two or three sheets of full-sized newspaper (not the tabloid size) on a table. Choose a smooth-surfaced table, not one with a table cloth. Position the paper so that the long edge runs along the edge of the table. Put a wooden yardstick or ruler under the newspaper so that half of it sticks out over the edge of the table. Smooth the papers flat. Now try to flip the newspaper two feet into the air by striking the ruler with a single, quick blow. Make sure the blow is quick. You can't do it. Put on safety goggles, just in case. WHY?



• Take a crisp new dollar bill and hold it about chest high. Put your hand at about the middle of the bill with thumb and index finger about an inch apart - but not touching the bill. Without warning, let go of the bill and see if you can catch it before it passes through your fingers. You can't do it. WHY?



• The Cartesian Diver goes down in the water when you squeeze the bottle and goes up when you release the bottle. WHY?



• Suspend a weight from a rubber band. Put a lighted match near the rubber band. The weight rises. WHY?



• The toy drinking bird with a liquid inside of it will continuously drink from a glass of water once it begins. WHY?



• The ratio of your height compared to the circumference of your head is about the same as everyone else's. WHY?



• Blow up a balloon about 1/3 of the way. While holding the balloon in your mouth, place a plastic cup on each side of the balloon. Continue to inflate the balloon until it is twice its size. When you remove your hands from the cups they stick to the balloon. WHY?



• Place a marble on a table and cover it with a glass jar. You can pick up the marble without touching it. WHY?



• A cork placed in a glass that is completely filled with water will always move to the center of the glass. WHY?



• Put some vaseline around the neck of a narrow-necked baby bottle. Take a peeled boiled egg and after dropping a lit match into the bottle, quickly put the egg on top of the bottle. The big egg will squeeze into the bottle. WHY?

The website Science Inquiry is helpful for identifying Discrepant Events to use with students.

Another good website for Discrepant Events is Wacky Science Experiments.