Exhibition date: January 23 - February 21, 1993
Key Ideas: Patterns, Predictability, Probability, Frequency
What About Patterns?
When we think of patterns, we may initially think of visual patterns such as those in fabric, wallpaper, art pieces. But patterns are so much more than that! Patterns are trends, such as radioactive decay and the colonization of intertidal zones. They are cycles, changes occuring over time, such as life cycles, seasonal cycles, planetary cycles and tidal cycles. There are even irregular patterns such as the predator-prey relationship and plant succession events.
Recognizing a pattern can help us make predictions about what happens next. Patterns help to tell us what to expect from our world.
What will we discover at Explorit?
You and your students will:
* explore the different kinds of patterns in everyday life.
* become aware of how to recognize a pattern.
* experiment with creating patterns in a variety of ways.
Questions to Tickle Your Mind:
* How many times does something have to happen to be a pattern?
* What are some patterns in your everyday life? Can you think of activities that aren't patterns?
* Can "random" events have a pattern? What is an example of a patterned "random" event?
* What is the difference between a pattern and a predictable pattern?
To help you apply the California Science Framework (1990), we have written the key words, or "big ideas," in boldface.
What is a pattern?
The answer may seem obvious, but a clear understanding of what a pattern is is crucial. According to Webster's, a pattern is a natural or chance configuration. Another definition is "a reliable sample of traits, tendencies, acts, or other observable characteristics of a person, [thing], group or institution." When we recognize a pattern in an event or thing, we may be able to make predictions based on that pattern. In other words, we are able to foretell an event because of past experience, observation or even scientific reason. Because there is a regularity, a pattern, of an occurance, we can guess at the future.
What are some common patterns?
Patterns touch us everyday of our lives; many of them are predictable. The changing of the seasons is a predictable pattern. The four seasons are accompanied by various patterns of weather, depending on where you live. Weather is less predictable, although we invest a great deal of energy in trying to forecast the weather.
Some natural phenomena seem to follow patterns, but usually we need many, many occurrences to help us distinguish the pattern. Earthquakes are an example of such a phenomena. For centuries, scientists around the world have tried to predict earthquakes with very limited success. The same is true for other natural phenomena such as tidal waves, volcano eruptions and severe storms such as hurricanes and tornadoes. Because these natural phenomena occur infrequently, we may have seen too little of the pattern to be able to recognize it and make accurate predictions.
Other patterns are human-made. For example, tossing a coin can reveal a predictable pattern. If nothing else, you can recognize that you have an equal chance of getting a head or tail with each throw. The same sort of predictability, or probability, also occurs with dice and cards. Probability is simply knowing the chance that something will occur.
What other patterns, either natural or human-made, can you think of? How often does a student get hurt on the playground? Or find a coin? Would tracking these occurrences reveal a pattern?
How do we use patterns?
We use patterns in a number of ways. For example, if you know that a seedling grew from a pinecone seed, you can make a fairly accurate prediction of what the grown tree will look like because you know the pattern of growth of most pine trees. The same is true for seeds from other plants and even animals. We know generally what a baby ostrich will look like as an adult. We can even make guesses at how a human baby or child will look at various older ages. Police use computers and advanced photographic techniques to age photographs of abducted children in order to help identify the child at an older age.
Scientists use visual patterns to classify plants and animals. The slight variations between two plants is sometimes a pattern that botanists can use to separate those plants into different species.
Animals not only have visual patterns but also behavioral patterns. Going back to the ostrich, if you were an expert in ostrich behavior, you could predict some of the behaviors of that ostrich as a chick or an adult. Similarly, we human beings have behavior patterns although some are more predictable than others. For instance, we are not surprised when someone cries if they are sad or have been physically hurt. Crying is an understandable behavior pattern for those circumstances.
In order to increase our stability or security, humans even organize their world according to predictable patterns. For example, when driving on the freeway, we expect that the majority of off-ramps will exit on the right side of the road. We can therefore anticipate our exit and (theoretically) move into the necessary lane far in advance of the off-ramp. Have you ever been surprised by an off-ramp that exits to the left? Left exits break from the usual pattern and can upset our sense of stability. Even rules for a game, policies for a school district, or laws for our country help us to predict the patterns of other peoples' behavior so that we can live with less concern for our safety and security.
1. Pattern Brainstorm
* Chalkboard or large piece of paper
* Appropriate writing implement
Lead a brainstorming session on patterns. Encourage your class to think of as many patterns as they can. Completely fill the board or use more than one piece of paper if necessary. Encourage the children to explain why they consider their contribution to be a pattern. If desired, expand this activity to include sorting all the suggestions into types of patterns.
* What makes something a pattern?
* When does a pattern help to predict?
2. Paper Patterns
* Scissors for each student
Experiment with the patterns one can make using scissors and paper. Try snowflakes and paper dolls, but expand your investigation of other paper patterns. The key is to encourage your class to make predictions of their patterns. For instance if they have folded the paper in half and cut out a semi-circular piece from the center of the folded edge, what will the paper look like when it is unfolded? Have them draw their predictions before they even open the paper.
* What was the easiest pattern to predict? The most difficult?
* What kinds of patterns can you make just by folding the paper (no cutting)?
3. Tree Prediction
* Writing implements for all
Think of a tree with which you and your class are familiar. Make a guess as to what that tree will look like at various stages of its life. Have your class compare their predictions with one another. How are the predictions similar? Different? Expand this activity by choosing another plant or animal to predict. You could even try human beings; each class member could predict what they will look like at an older age.
* How can you check if your predictions are true?
* Do trees and plants always adhere to the usual pattern of growth? What makes them diverge from that pattern?
4. Class Height Pattern
* A large chalkboard or very long sheet of paper
* A writing implement
Have your students line up, shortest to tallest, along a wall with the blackboard or paper behind them. Mark the height of each child on the board or paper, and write "B" or "G" above their name to indicate boy or girl. Have the students return to their seats and discuss the pattern of heights on the board.
* Did any kind of pattern emerge? What does this tell you about your class? What does it tell you about other classes of the same age in your school?
* Do you think all children of a similar age would fit into the pattern that your class created? Why or why not?
5. Coin Patterns
* Several coins
* Paper and pencil
* Chalkboard or large piece of paper
Having the students work in pairs or small groups, instruct the students to flip their coin 20 times. Each time, a recorder in the group should write down whether the flip resulted in a head (H) or tail (T). Once all flips are completed, the students should total the number of heads and tails and write them on the chalkboard or a large piece of paper.
* What pattern emerges? (Make sure that you mention that coin flipping is a simple example of a random event.)
* Did all groups have the same number of heads and tails? Why or why not?
* Would a different pattern emerge if the groups had tossed the coin fewer times? What about more times?
* Would you have the same results if you did the same activity again tomorrow? Why or why not?
6. Shadow Patterns
* A large area outside covered with asphalt or concrete
* A sunny day
Early in the day, have the class go outside and, working with partners, outline the shadow of each other on the blacktop. Repeat this process approximately one hour later. Do it again after another hour has passed. This time ask the students to predict where their shadow will be after another hour. Then repeat the process once more after another hour.
* Was the last prediction accurate? Why or why not?
* What pattern are you relying on to make predictions about your shadow's position?
1. Pattern - a natural or chance configuration. Another definition is a reliable sample of traits, tendencies, acts, or other observable characteristics of a person, thing, group or institution.
2. Predict - to foretell an event because of past experience, observation or even scientific reason.
3. Frequency - the number of repetitions in a unit of time.
4. Probability - knowing the chance that something will occur.
5. Periodicity - the quality, state or fact of being regularly recurrent.
6. Model - a pattern of something that exists or something to be made.
7. Random - lacking predictability (no way to predict a partcular outcome) but possibly having a pattern.
8. Chaos - a chaotic event develops no pattern no matter how many times it is repeated.
Ahlgren, A. and Halberg, F. (1990) Cycles of Nature: An Introduction to Biological Rhythms. (Rhythms are another type of pattern! Good for grades 6 and up.)
DeBruin. J. (1989) School Yard - Backyard Cycles of Science. (Cycles are patterns, too! Best for grades 3 and up.)
Exploratorium Quarterly (Summer 1992. Volume16, Number 2.) Patterns (A collection of articles and a section on things to do and notice.
Patterns in the World. (1992) National Wildlife Federation.
Brodath, P. (1966) Textures. New York: Dover Publications.
Stevens, P.S. (1977) Patterns in Nature.
Findly, R. (1981) "Mountain with a Deathwish." National Geographic, 159(1). (Story of Mount St. Helen's.)
Funk, B. (1980) "Hurricane!" National Geographic, 158(3). (Discusses the nature and pattern of hurricanes.)
Canby, T.V. (1990) "Earthquake: Prelude to the Big One?" National Geographic, 177(5). (Story of recent Loma Prieta earthquake in California.)
Vesilind, P.J. "Monsoons: Life Breath of Half the World." National Geographic, 166(6).
Gleick, J. (1987) Chaos: Making a New Science. New York: Penguin Books. (A whole book on the subject of chaos. Definitely for adults.)
Hann, J. (1991) How Science Works. Pleasantville, NY: Reader's Digest Association, Inc. (A great resource for all science topics. Good illustrations and photography.)
Strongin, H. (1991) Science on a Shoestring. Menlo Pk., CA: Addison-Wesley Publishing Co. (Another good general science book.)
DeVito, A. (1989) Creative Wellsprings for Science Teaching. W. Lafayette, IN: Creative Ventures, Inc.(Good general science book.)
Science For Children: Resources for Teachers. (1988) National Science Resources Center. Washington, D.C: National Academy Press. (Fantastic sourcebook for teachers containing curriculum, book and location resource references.)
Druger, M. (1988) Science for the Fun of It. (A great book on informal science education. Marvin Druger has also worked with "NOVA" and "3-2-1 Contact.")
Science Activity Book (1987) Smithsonian Institution.
More Science Activities (1988) Smithsonian Institution.
Still More Science Activities (1989) Smithsonian Institution.
A series from one of the best museums in the world. Full of fun, science activities on a variety of topics.
An Explorit Science Center "Science Byte":Chaos.
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