The Motivational Power of Science Discrepant Events.docx

7/28/2019 The Motivational Power of Science Discrepant Events.docx

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The Motivational Power of Science Discrepant Events

Thomas R. Koballa, Jr.

Department of Science Education

University of Georgia

An attention getting, thought-provoking approach to initiate inquiry is

through the use of discrepant events. A discrepant event puzzles the observer,causing him or her to wonder why the event occurs as it did. These situations

leave the observer at a loss to explain what has taken place. Discrepant events

influence equilibration and the self-regulatory process, according to the Piagetiantheory of intellectual development. Situations that are contrary to what a person

expects cause him or her to wonder what is taking place, resulting in cognitive

disequilibrium. With proper guidance, the individual will attempt to figure out thediscrepancy and search for a suitable explanation for the situation. When a personarrives at a plausible explanation for a discrepant event, he or she will establish

cognitive equilibrium at a new level. The individual is now better equipped

mentally to approach new situations that cause curiosity and puzzlement (Piaget,1971).

An inquiry session initiated with a discrepant event can begin with a

demonstration, preceded by directions to focus students attention on what they areabout to observe. The discrepant event approach receives support from cognitive

psychologists, because of its potential impact on learning.

This workshop focuses on the exploration of selected science discrepantevents using a three-step model developed by Alfred Friedl. The steps of Friedls

model are: (1) Set Up the Discrepant Event - Students are confronted withquestions or problems that gain attention, increase motivation, pose question, and

reveal misconceptions. (2) Involve the Students in Solving the Discrepancy -

Students engage in purposeful activity in attempting to resolve the discrepancy.

(3) Resolve the Questions Posed by the Events and Relate Them to Body ofScience Knowledge - Students will resolve the event themselves or with teacher

assistance. By experiencing science discrepant events using this model, students

will sharpen their skills of observing, predicting, gathering data, andexperimenting. They will then be ready for further study of the science concept

targeted by the discrepant event.

Sample Discrepant Events

Science teachers have used the discrepant events presented below fordecade. The descriptions of the events are from Teaching Science to Children:


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An Integrated Approach by Alfred Friedl (1986). When used to introduce science

concepts, these discrepant events are best presented as teacher demonstrations.Appropriate safety precautions should be taken when performing any science

discrepant event.

Station A: InertiaThe First Law of Motion

The first law of motion states that an object at rest tends to remain at rest andan object in motion tends to stay in motion.

Activity 1: Coin in the Cup

Place a note card on top of a glass of water, and place a coin on top of the note

card. Without touching the coin or tilting the cup, try to get the coin into the cup.

Investigation: (1) Try different ways of moving the card to accomplish the task;

(2) Study the action of the coin when the card is quickly moved; and (3) Thinkabout the effect of inertia on the coin.

Explanation: The coin remains at rest if the card is pulled quickly. You can snap

the card out with your finger. The card will move fast, and the coin will stay atrest. When the card is removed, the coin will drop into the cup.

Activity 2: Antigravity BucketPour about an inch of water into a bucket. Then swing the bucket in a large

upright circle with your arm. Does the water pour out or stay in the bucket?

Investigation: (1) Observe that the water remains in the bucket when it is swung

overhead; (2) If performed outdoors, determine what speed the water begins to fallfrom the bucket; (3) Infer a relationship between the swinging speed and the

tendency for the water to stay in the bucket.

Explanation: The swinging bucket puts the water in motion. Once in motion, thewater tends to keep moving in a straight line. With the bucket moving in a circle,

the water pushes against the bottom of the bucket as it attempts to stay in a

straight line. The push is sufficient to overcome the force of gravity.

Station 2: Air Pressure

Air is all around us and exerts pressure.

Activity 3: Is a Newspaper Stronger than a Board?


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Lay a thin board on a table so that one end extends over the edge by 15 to 30

centimeter. Place a sheet of newspaper over the portion of the board on the table.What will happen when you slowly push down on the end of the board extending

beyond the table? When you hit the extending part of the board with a sharp blow?

Investigation: (1) When you push down on the end of the board, predict that the

board will lift the newspaper; (2) See that the board is broken when hit sharply; (3)Infer that some form of pressure is exerted when the board is hit hard; (4) Develop

a theory to explain what holds down the newspaper.

Explanation: When the end of the board is hit, air pressure pushes down on the

newspaper with such force that the board is broken. If the board is pushed downslowly, air can get under the newspaper from the sides to equalize the pressure, and

the paper is easily lifted.

Activity 4: Stop the LeakPut a nail hole in the top and in the bottom of a plastic bottle. Fill the bottle with

water and seal the lid. The water will run out of the bottle. How can you stop the

flow of water with your finger without getting it wet?

Investigation: (1) Observe that the water will stop flowing when the top opening is

closed; (2) Infer that a force acts to hold the water in when the top opening isclosed.

Explanation: Air enters the top hole, when water runs out the bottom hole. Whenthe top hole is sealed, the air pressure inside the bottle is less than outside.

Therefore, greater air pressure is exerted against the bottom hole from the outsidethan exerted from inside the bottle. The difference in air pressure causes the water

to stop running.

Station C: Adhesion and Cohesion

Adhesion is the attraction between unlike objects. Cohesion is the attraction

of like molecules for each other. There are differences in the cohesive forces of

solids, liquids, and gases. Water is affected by both adhesion and cohesion. Wateris attracted to many substances (adhesion), and there is also an attraction among

water molecules for each other (cohesion)

Activity 5: Cork in the Middle

Place a small cork in the middle of a partly filled glass of water. What happens tothe cork? Try to make the cork stay in the middle.


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Investigation: (1) Observe that the cork moves to the side of the glass even whenthe cork is placed in the middle; (2) Observe that the water level in the middle of

the glass is slightly lower than the water touching the side of the glass; (3) Try to

keep the cork in the middle.

Explanation: This activity shows the force of adhesion. The water is curvedupward where it touches the glass because of adhesion. The cork floats to the

highest point in the water. The highest point is around the edge where the watertouches the glass.

Activity 6: Join the WaterPunch several holes close together at the bottom of a plastic bottle and fill it with

water.

Investigation: (1) Observe how the water comes out of the holes; (2) Try to makethe water streams join together to form a single stream.

Explanation: This activity shows the cohesive forces within water. The water willflow from the holes in separate streams until you use your finger to pull the

streams together. Once joined, the streams tend to stay together.

Station D: Molecular Motion and States of Matter

Matter is composed of atoms, and atoms are mostly space. This is true for

water and for substances with greater density like iron and stone. Just about allmatter on earth exists in one of three phases: solid, liquid or gas. All common

gases, including oxygen, hydrogen, and carbon dioxide, are invisible.

Activity 7: Does 3 + 3 = 5?

Pour 50 milliliters of alcohol into a graduated cylinder. Then, pour 50 milliliters of

water into the same graduated cylinder. Read the level of liquid in the graduatedcylinder at its lowest point in the meniscus.

Investigation: (1) Identify the liquids as alcohol and water; (2) Observe traces ofliquid inside the contains first holding the liquids; (3) Recognize that the traces of

liquid could not account for the loss in volume; (4) Observe when two volumes of

water (and alcohol) are poured together there is no loss of volume; (3) Infer thatthe loss of volume is due to space between water and alcohol molecules.


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Explanation: When 50 milliliters of water are added to 50 milliliters of alcohol, the

volume of the two mixed together is only about 96 or 97 milliliters. When mixedtogether, the combined molecules fit together better than when they are alone, so

they take up less space.

Activity 8: What Put Out the Fire?

Place a small candle inside a beaker and add a small amount of baking soda andwater. The light the candle and pour a small amount (about 10 mL) of vinegar into

the beaker, being careful not to touch the candle flame. Why does the flame go outwhen you pour liquid into the beaker?

Investigation: (1) Observe foaming action when the vinegar touches the bakingsoda. (2) Infer that a substance is produced by the foaming action that causes the

flame to go out.

Explanation: This activity shows the existence of an invisible substance that putout the fire. When vinegar is poured into the dissolved baking soda, carbon

dioxide is released. The carbon dioxide fills the beaker, pushing out the oxygen

and extinguishing the flame.

Bibliography

Chiappetta, E. L., & Koballa, T. R. (2002). Science instruction in the middle andsecondary schools. Upper Saddle River, NJ: Merrill/Prentice Hall.

Friedl, A. E. (1986). Teaching science to children: An integrated approach.

New York: Random HousePiaget, J. (1971). Biology and knowledge. Chicago: University of Chicago Press.


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The Motivational Power of Science Discrepant Events

Thomas R. Koballa, Jr.

Professor and HeadDepartment of Science Education

University of Georgia


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Discrepant Event Teaching Model

(1) Set Up the Discrepant EventStudents are confronted with questions or problems that gain attention,

increase motivation, pose question, and reveal misconceptions.

(2) Involve the Students in Solving the DiscrepancyStudents engage in purposeful activity in attempting to resolve the

discrepancy.

(3) Resolve the Questions Posed by the Event and Relate Them to Body of ScienceKnowledge

Students will resolve the event themselves or with teacher assistance.


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The Motivational Power of Science Discrepant Events.docx