Teacher
The Puzzle Theory: Difference between Law vs. Theory
(Adapted from pbs.org “Evolution” series)
NGSSS:
SC.912.L.15.8 Describe the scientific explanations of the origin of life on Earth. (AA)
SC.912.L.15.1: Explain how the scientific theory of evolution is supported by the fossil record,
comparative anatomy, comparative embryology, biogeography, molecular biology, and observed
evolutionary change. (AA)
SC.912.N.1.3: Recognize that the strength or usefulness of a scientific claim is evaluated
through scientific argumentation, which depends on critical and logical thinking, and the active
consideration of alternative scientific explanations to explain the data presented.
SC.912.N.1.6: Describe how scientific inferences are drawn from scientific observations and
provide examples from the content being studied.
SC.912.N.3.1: Explain that a scientific theory is the culmination of many scientific investigations
drawing together all the current evidence concerning a substantial range of phenomena; thus, a
scientific theory represents the most powerful explanation scientists have to offer.
SC.912.N.3.4: Recognize that theories do not become laws, nor do laws become theories;
theories are well supported explanations and laws are well supported descriptions.
Purpose of the Lab/Activity:
 Modeling how a theory is developed over time
 Follow the procedure to model “discoveries through time” and how they change.
 Model the way these theories are based on evidence found and are subject to change
according to new discoveries and increases in technology.
Prerequisites:
 Understand the role of observations in science.
 A general sense of what a hypothesis or theory is
 Give students practice using evidence to make inferences.
 A general sense of the difference between a theory and a law
Materials:
 1,000 piece puzzle with a picture of
nature having many factors and
colors. Try to stay away from
repeated patterned pictures



6-8 envelopes
6-8 Large newsprint or poster paper
Copies of the student handout
Procedures: Day of Activity: (per group)
What the teacher will do:
1. Preparation: Remove all edge pieces from the puzzle. Divide the remaining
pieces of the jigsaw puzzle evenly into the six or eight envelopes. Be sure
to put the puzzle box with the picture out of students’ sight
Before
2. Group students into six to eight teams.
activity:
ENGAGE:
3. Have a class discussion using a KWL or other pre-assessment strategies to
determine what the students know about the scientific process. Examples of
questions include:
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a. What is a hypothesis? (Answers will vary. Guide the discussion so
that it includes the steps any person takes to answer a question.)
b. What ideas do we come up with when a car does not start? How do
we try to solve the problem? (Answers will vary, but guide them
towards different questions about why the car won’t start and what
things can be done to test why it won’t start.)
c. What is the difference between a theory and a law? (Answers will
vary, but DO NOT give the students the answer. Write some of the
responses on the board to review and discuss after the completion of
the activity.)
4. Introduce the activity by telling students they will explore the nature of
science, using evidence (jigsaw puzzle pieces) to develop a series of
tentative hypotheses to explain the scene represented by the puzzle pieces.
5. Give each group an envelope containing the puzzle pieces and piece of
large newsprint or poster paper.
6. Remind them to NOT look at the puzzle pieces inside the envelope until you
tell them what to do. Give out the student handouts, AFTER the discussion.
What the teacher will do:
During
activity:
EXPLORE:
Describe these scenarios to the students and guide them through the process
of developing their theories and hypotheses in each of their groups based on
their “evidence”. The puzzle pieces represent the evidence found by scientists
over time and the amount of pieces represent the amount collected because of
available technology during the time period defined. Make sure to give enough
time in between each scenario to develop the hypotheses and/or draw their
“theory” picture.
Use these descriptions below loosely as your script to guide the students:
1. First discovery in the 1600’s: Remove one piece of the puzzle from
the envelope. Write a hypothesis that best describes what your group
thinks the picture on the puzzle will look like.
2. Second discovery early 1800’s: Each team should now remove 10
pieces of the puzzle from the envelope. After examining the pieces,
develop a second hypothesis about the complete scene or picture
shown represented by the puzzle. Identify the key evidence used to
support the hypothesis.
3. Third discovery early 1900’s: Remove another 15 pieces of the puzzle
from the envelope and either retain or revise your 1st and 2nd hypotheses
or develop a 3rd hypothesis. Again cite the key evidence should be
identified.
4. Fourth discovery late 1900’s with better technology: Now remove an
additional 20 puzzle pieces from the envelope and proceed as in step 3.
Collective evidence seen and develop a final hypothesis. State your
hypothesis and the evidence you’ve accumulated to support it. NOW
DRAW WHAT YOU THINK THE PICTURE WILL LOOK LIKE. Unused
puzzle pieces should remain in the envelope.
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EXPLAIN:
Closing: Show the students the picture from the box. It is suggested that the
picture be scanned and put up on a projector to increase interest in the reveal
moment. Be flexible at this stage of the activity. Rather than each group
answering each question individually, the entire class could be engaged in a
discussion based on their answers.
5. Have the groups each share their hypotheses and pictures for their
“puzzle theories”. As a class, discuss the similarities and differences
between the groups and the actual picture.
6. Discuss again the difference between a theory and a law. Refer and
compare to the answers that were written on the board before the
activity. (A scientific theory summarizes a hypothesis or group of
hypotheses that have been supported with repeated testing. A theory is
valid as long as there is no evidence to dispute it. Therefore, theories
can be disproven. Basically, if evidence accumulates to support a
hypothesis, then the hypothesis can become accepted as a good
explanation of a phenomenon. One definition of a theory is to say it's an
accepted hypothesis. A law generalizes a body of observations. At the
time it is made, no exceptions have been found to a law. Scientific laws
explain things, but they do not describe them. One way to tell a law and
a theory apart is to ask if the description gives you a means to explain
'why'. Example: Consider Newton's Law of Gravity. Newton could use
this law to predict the behavior of a dropped object, but he couldn't
explain why it happened.)
What the teacher will do:
After
activity:
ELABORATE:
After discussing the different theories, the teacher should ask these questions
and facilitate a closing review of the activity and discussion: (Answers will vary.
Students can write some of the responses in their journals in order to give them
information to use on their evaluation piece.)
 What kinds of information from the pieces were valuable to your team in
formulating a hypothesis? Answers will vary.
 How did the personal biases of people in your group affect your
hypotheses? Answers will vary.
 How did your initial hypothesis compare to your final hypothesis and
how did collaboration with other teams affect your final hypothesis?
Answers will vary.
 Did different groups have different hypotheses based on similar
evidence? How is this possible? Answers will vary.
 Is your final hypothesis “correct”? Explain. What degree of certainty do
you have about your hypothesis? Answers will vary.
 How does this simulation compare to the process of science in the real
world? Answers will vary.
 How does not having the “edges” of the puzzle relate to the nature of
science? Answers will vary.
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EVALUATE:
Assign these questions to the students to answer individually in their journals/
handout/ paper. Can be assigned as a home learning grade or quiz grade
during class the next day. It is suggested that a rubric be created.
Answer Key for Results/Conclusion:
1. Teams should share their hypotheses. Is there a consensus regarding the
hypothesis that best fits the evidence? Explain why or why not. Answers
will vary. Most likely it will be no and the students will describe the
discussions that took place.
2. What evidence was most useful in developing and evaluating your hypotheses?
(Students should discuss specific puzzle pieces that guided their ideas.)
3. Was any information misleading and result in the development of a hypothesis
that had to be rejected as new evidence was found? (Students should discuss
specific puzzle pieces that guided their ideas.)
4. Did any personal biases within your group influence the development and
evaluation of one or more of your hypotheses? (Students should discuss
specific ideas from group members.)
5. How did your final hypothesis compare with your 1st hypothesis? (Most likely it
will be different. Make sure they explain why.)
6. How did collaboration with other teams affect your final hypothesis? (Students
should discuss how hearing the similarities and differences with other groups
guided their ideas.)
7. Did similar evidence used by more than one team result in different
hypotheses? (Answers will vary.)
8. Did different evidence used by more than one team result in identical or very
similar hypotheses? (Answers will vary.)
9. What degree of certainty did you have about your final hypothesis? Why?
(Answers will vary, but students should be clear on why they were so sure of the
hypothesis.)
10. Did the absence of the “edges” of the puzzle influence the level of difficulty in
developing your hypotheses? (Answers will vary, but students should discuss
how if they had the edges they would have developed their hypothesis or theory
more quickly.)
11. If you only had “edges” to use would you have any advantages or limitations?
(Edges help to finalize the picture faster because it is clear where the piece or
evidence belongs.)
12. Are there edges that limit or “pin in” scientists as they explore and investigate
various questions and problems? (Answers will vary, but students should
explain their ideas.)
13. How are the “edges” like a theory early in its development? (Answers will
vary, but students should explain their ideas.)
14. What scientific or medical advances have occurred during your lifetime
through the steady accumulation of evidence? (Answers will vary, but students
should explain their ideas.)
15. How did this activity model the process of science used as individuals seek
answers to question and problems? (Answers will vary, but students should
explain their ideas.)
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EXTEND: (to be answered in an assessment journal prompt)
Later in the study of evolution, discuss how Darwin and others have studied evidence from
various sources that led them to conclude that life has changed, or evolved, over time and that
organisms living today are descendants of those that have lived in the past. For example, as
Charles Darwin completed his voyage on the Beagle, the plants and animals he saw in various
locations that did not exist in England puzzled him. He also noted the variation in domestic
animals. He was puzzled by this variation. After studying much evidence, he wrote the
following:
When I visited during the voyage of the H.M.S. Beagle, the Galapagos
Archipelago, I fancied myself brought near to the very act of creation. I often
asked how these many peculiar animals and plants had been produced: the
simplest answer seemed to be that the inhabitants of the several islands have
descended from each other, undergoing modification in the course of their
descent; and that all the inhabitants of the archipelago were descended from
those of the nearest land, namely America.” (From Variation of Animals
published in 1868) (Quoted in Larson, Edward J. 2001. Evolution’s Workshop.
New York: Basic Books, p. 85)
Darwin’s challenge, or puzzle, was to explain the variation he saw in life. He studied evidence
from many sources, read widely, and thought through various hypotheses before he arrived at
his conclusion published in 1868. When he left England on the voyage of the Beagle, the
boundaries or “edge” of his puzzle was extended as he left the confines of England. However,
the boundaries or “edge” of the scientific process were such that he was required to support his
hypotheses with evidence. Other scientists who have attempted to explain the diversity of life
on Earth have had to deal with self-made and imposed boundaries, or “edges”, which restrained
their work and sometimes led them to hypotheses that could not be supported with evidence.
Exit Slip Question: (write this on a piece of paper and turn in before you leave)
“Are the edges important to the discoveries? Do they restrict science in its research? Explain an
example where this might occur and what can be done to allow for free scientific thought?”
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Teacher
The Puzzle Theory: Difference between Law vs. Theory
NGSSS:
SC.912.L.15.8 Describe the scientific explanations of the origin of life on Earth. (AA)
SC.912.L.15.1: Explain how the scientific theory of evolution is supported by the fossil record,
comparative anatomy, comparative embryology, biogeography, molecular biology, and observed
evolutionary change. (AA)
SC.912.N.1.3: Recognize that the strength or usefulness of a scientific claim is evaluated
through scientific argumentation, which depends on critical and logical thinking, and the active
consideration of alternative scientific explanations to explain the data presented.
SC.912.N.1.6: Describe how scientific inferences are drawn from scientific observations and
provide examples from the content being studied.
SC.912.N.3.1: Explain that a scientific theory is the culmination of many scientific investigations
drawing together all the current evidence concerning a substantial range of phenomena; thus, a
scientific theory represents the most powerful explanation scientists have to offer.
SC.912.N.3.4: Recognize that theories do not become laws, nor do laws become theories;
theories are well supported explanations and laws are well supported descriptions.
Background: Words have precise meanings in science.
For example, 'theory', 'law', and 'hypothesis' don't all mean
the same thing. Outside of science, you might say
something is 'just a theory', meaning it's supposition that
may or may not be true. In science, a theory is an
explanation that generally is accepted to be true.
A hypothesis is a statement based on observation. Usually,
a hypothesis can be supported or refuted through
experimentation or more observation. A hypothesis can be
disproven, but not proven to be true. Example: If you see no
difference in the cleaning ability of various laundry
detergents, you might hypothesize that cleaning
effectiveness is not affected by which detergent you use.
A scientific theory summarizes a hypothesis or group of hypotheses that have been supported
with repeated testing. A theory is valid as long as there is no evidence to dispute it. Therefore,
theories can be disproven. Basically, if evidence accumulates to support a hypothesis, then the
hypothesis can become accepted as a good explanation of a phenomenon. One definition of a
theory is to say it's an accepted hypothesis. Example: It is known that on June 30, 1908 in
Tunguska, Siberia, there was an explosion equivalent to the detonation of about 15 million tons
of TNT. Many hypotheses have been proposed for what caused the explosion. It is theorized
that the explosion was caused by a natural extraterrestrial phenomenon, and was not caused by
man. Is this theory a fact? No. The event is a recorded fact. Is this this theory generally
accepted to be true, based on evidence to-date? Yes. Can this theory be shown to be false and
be discarded? Yes.
A law generalizes a body of observations. At the time it is made, no exceptions have been found
to a law. Scientific laws explain things, but they do not describe them. One way to tell a law and
a theory apart is to ask if the description gives you a means to explain 'why'. Example: Consider
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Newton's Law of Gravity. Newton could use this law to predict the behavior of a dropped object,
but he couldn't explain why it happened.
As you can see, there is no 'proof' or absolute 'truth' in science. The closest we get are facts,
which are indisputable observations. Note, however, if you define proof as arriving at a logical
conclusion, based on the evidence, then there is 'proof' in science. What is important is to
realize they don't all mean the same thing and cannot be used interchangeably.
(http://chemistry.about.com/od/chemistry101/a/lawtheory.htm)
Scientists formulate theories by observing nature and analyzing evidence—or using the
scientific process. In this activity, student teams use evidence (jigsaw puzzle pieces) revealed
over time to experience the nature of science and understand its limitations.
Purpose of the Lab/Activity:
 Modeling how a theory is developed over time
 Follow the procedure to model “discoveries through time” and how they change.
 Model the way these theories are based on evidence found and are subject to change
according to new discoveries and increases in technology.
Instructions:
1. Use evidence from a jigsaw puzzle to make inferences.
2. Use a jigsaw puzzle as a model of a scientific investigation.
3. Follow the directions from the instructor in order to model the way in which a scientific
investigation can occur.
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Puzzle Theory: Difference between Law vs. Theory (Time Line)
Fill these out with your group as your instructor guides you through the process.
1. First discovery in the 1600’s (first hypothesis):
_______________________________________________________________________
_______________________________________________________________________
Key evidence used to determine: ____________________________________________
Second discovery early 1800’s (second hypothesis)::
_______________________________________________________________________
_______________________________________________________________________
Key evidence used to determine: ____________________________________________
2. Third discovery early 1900’s (third hypothesis):
_______________________________________________________________________
_______________________________________________________________________
Key evidence used to determine: ____________________________________________
3. Fourth discovery late 1900’s with better technology (FINAL hypothesis):
_______________________________________________________________________
_______________________________________________________________________
Key evidence used to determine: ____________________________________________
Hypothetical Picture based on FINAL hypothesis- (This is a DRAFT. Draw a final on the larger
paper)
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Teacher
Puzzle Theory
EVALUATION:
Questions to answer individually in your journals/ handout/ paper: (Choose 10 of the 15
to answer individually)
1. Teams should share their hypotheses. Is there a consensus regarding the hypothesis that
best fits the evidence?
2. What evidence was most useful in developing and evaluating your hypotheses?
3. Was any information misleading and result in the development of a hypothesis that had to be
rejected as new evidence was found?
4. Did any personal biases within your group influence the development and evaluation of one
or more of your hypotheses?
5. How did your final hypothesis compare with your 1st hypothesis?
6. How did collaboration with other teams affect your final hypothesis?
7. Did similar evidence used by more than one team result in different hypotheses?
8. Did different evidence used by more than one team result in identical or very similar
hypotheses?
9. What degree of certainty did you have about your final hypothesis? Why?
10. Did the absence of the “edges” of the puzzle influence the level of difficulty in developing your
hypotheses?
11. If you only had “edges” to use would you have any advantages or limitations?
12. Are there edges that limit or “pin in” scientists as they explore and investigate various questions
and problems?
13. How are the “edges” like a theory early in its development?
14. What scientific or medical advances have occurred during your lifetime through the steady
accumulation of evidence?
15. How did this activity model the process of science used as individuals seek answers to question
and problems?
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