Nature of Science Woodrow Wilson Indiana Teaching Fellowships Summer 2010

SCIENCE is… the search for relationships that explain and predict the behavior of the universe.

Science has also been described as the process of model building, in which models serve to simplify observed phenomena and relationships. See Gilbert & Boulter (2000) Scientific “models” may exist in several forms: Physical (concrete; 3D objects) Gestural (kinesthetic; body movements) Verbal (spoken/written; analogy; metaphor) Pictorial (visual diagrams; animations) Numerical (data table; lists) Graphical (ordered pairs) Mathematical (equations; formulas)

Scientific Hypothesis Most people agree that a scientific hypothesis can be defined simply as an educated guess. We should, however, stress that it is educated, meaning that there are plausible reasons for that decision.

Scientific Theory There is much misunderstanding about what constitutes a scientific theory. “In science, a theory is a mathematical or logical explanation, or a testable model of the manner of interaction of a set of natural phenomena, capable of predicting future occurrences or observations of the same kind, and capable of being tested through experiment or otherwise falsified through empirical observation. of interaction of a set of natural phenomena, capable of predicting future occurrences or observations of the same kind, and capable of being tested through experiment or otherwise falsified through empirical observation.” Taken from

Scientific Law A scientific law has been described as a statement describing a natural event. In many cases, scientific laws tend to DESCRIBE events, while scientific theories tend to EXPLAIN events. It is NOT a question of TRUTH.

The Scientific Method Many students of all ages are taught that “the scientific method” consists of steps such as: 1) Make observation 2) Formulate hypothesis 3) Test hypothesis 4) Evaluate hypothesis 5) Change hypothesis and/or make more tests It is important to note that scientific study involves a systemic process of It is important to note that scientific study involves a systemic process of experimentation and evaluation, whether you begin with a hypothesis or with “trial and error.” experimentation and evaluation, whether you begin with a hypothesis or with “trial and error.”

Joel A. Bryan, Ph.D. Department of Physics and Astronomy Ball State University

It is the year The Earth’s It is the year The Earth’s natural resources are exhausted. natural resources are exhausted. Scientists have determined that Scientists have determined that the Earth will most likely explode the Earth will most likely explode in a very short time. in a very short time. Bang!!!

The development of space travel The development of space travel and other technological advancements and other technological advancements have enabled scientists to prepare a have enabled scientists to prepare a distant planet for human habitation. distant planet for human habitation.

You and a few others are fortunate to You and a few others are fortunate to have been selected as representative have been selected as representative members of planet Earth who will members of planet Earth who will survive and populate this new distant survive and populate this new distant planet. planet.

Upon arrival, you are relieved to find Upon arrival, you are relieved to find that the planet is indeed suitably that the planet is indeed suitably prepared for human existence, just prepared for human existence, just as promised. as promised.

Your joy soon turns to Your joy soon turns to frantic dismay when you frantic dismay when you discover that the sole discover that the sole member of your team with member of your team with knowledge of the voice- knowledge of the voice- activated oxygen producing activated oxygen producing machine has taken deathly machine has taken deathly ill and no longer remembers ill and no longer remembers the voice activation code. the voice activation code.

As your oxygen supply quickly depletes, As your oxygen supply quickly depletes, a close inspection of the voice- a close inspection of the voice- activated oxygen supply machine activated oxygen supply machine reveals only a few vague instructions. reveals only a few vague instructions. Oxygen Speak here. Instructions

“Oxygen is produced by spoken numerical code, of which no number may be used more than once. Five consecutive invalid attempts will cause this device to completely self-destruct. Press here to begin, speaking loudly and clearly into the microphone.”

Your task is to begin the process of trying to determine the “code,” or rule, that determines whether or not a number is valid for oxygen production.

You should begin with a “trial and error” type process that quickly leads you to form some kind of theory regarding what constitutes “successful” numbers. Both successful and unsuccessful responses should be recorded to assist your evaluation.

Works Doesn’t Work 2,4,6, 1,3,5, For example, these results might suggest to some that even #’s work and odd #’s do not.

You must then go through a “scientific” process of testing, evaluation, and modification of your theories. This process should illustrate what is commonly referred to as the “scientific method,” along with many attributes of the “nature of science.”

This activity provides opportunities during the entire process to illustrate aspects of the nature of science. Additional time should be taken at the end of the exercise to reflect on the nature of science as evidenced by this activity. The following is a brief discussion of how this activity illustrates some aspects of the nature of science.

 Scientific conclusions depend on the creative imagination of on the creative imagination of the scientist. the scientist. aspects reinforced by this activity include, but are not limited to: Nature of Science

 Science is a social enterprise.  Scientific knowledge is dynamic and subject to change. and subject to change.  Absolute certainty of a scientific conclusion is scientific conclusion is impossible. impossible.

Scientific conclusions depend on the creative imagination of the scientist. Participants were limited in Participants were limited in their creativity by what they their creativity by what they had previously experienced had previously experienced with numbers. with numbers.

Each participant looked at the Each participant looked at the exact same “evidence,” yet exact same “evidence,” yet depended on their own experiences depended on their own experiences and creative imagination to and creative imagination to determine the “reality” of what determine the “reality” of what the numbers actually represented. the numbers actually represented. This naturally led to differing This naturally led to differing interpretations of the same interpretations of the same “reality.” “reality.”

In what ways are the “creative” aspects of this activity similar to “creative” aspects of “real” science? In what ways are they different? How might prior experiences influence scientific interpretations? Provide some possible examples.

Science is a social enterprise. Because repeated failure would Because repeated failure would be detrimental to the health be detrimental to the health of all, it was necessary for of all, it was necessary for participants to reach some type participants to reach some type of consensus before attempting of consensus before attempting a “trial.” a “trial.”

Participants were forced to Participants were forced to evaluate competing theories evaluate competing theories and determine the most plausible. and determine the most plausible. This decision may not have always This decision may not have always been made on the basis of merit been made on the basis of merit alone. alone.

In what ways are the social aspects of this activity similar/different to the social aspects of “real” science? How are differences of opinion settled in scientific issues? Provide some possible examples.

Scientific knowledge is subject to change. A “theory” remains valid as A “theory” remains valid as long as it explains prior long as it explains prior findings and is useful in findings and is useful in predicting new ones. predicting new ones.

The “theories” were valid and The “theories” were valid and useful until new “discoveries” useful until new “discoveries” proved them wrong. proved them wrong. Theories may undergo slight Theories may undergo slight change or total abandonment change or total abandonment when confronted with when confronted with discrepant evidence. discrepant evidence.

In what ways are the aspects of theory change in this activity similar/different to the theory change aspects of “real” science? How does one decide whether to abandon or modify an existing theory? Provide some possible examples.

Absolute certainty of a scientific claim is impossible. No amount of trials could ever No amount of trials could ever prove one theory totally correct. prove one theory totally correct. Only one counterexample was Only one counterexample was needed to invalidate a theory. needed to invalidate a theory.

No one will ever No one will ever know with absolute know with absolute certainty the true certainty the true “rule” for the “rule” for the oxygen machine oxygen machine without seeing without seeing the “card.” the “card.”

In what ways are the uncertainties of this exercise similar/different to that of “real” science? What would “seeing the card” mean? Will scientists ever “see the card?” Provide some possible examples.

Aspects of the “Nature of Science”… Adapted from Science for All Americans (link) link and Benchmarks for Science Literacy (link) link The World Is Understandable The World Is Understandable Scientific Ideas Are Dynamic and Subject To Change Scientific Ideas Are Dynamic and Subject To Change Scientific Knowledge Is Durable Scientific Knowledge Is Durable Science Cannot Provide Complete Answers to All Science Cannot Provide Complete Answers to All Questions (the “realm of science”) Questions (the “realm of science”) Science Demands and Depends on Evidence Science Demands and Depends on Evidence Science Is a Blend of Logic and Imagination Science Is a Blend of Logic and Imagination Science Explains and Predicts Science Explains and Predicts

Scientists Try to Identify and Avoid Bias Scientists Try to Identify and Avoid Bias Absolute Certainty of a Scientific Conclusion is Absolute Certainty of a Scientific Conclusion is Impossible (“Science Is Not Authoritarian”) Impossible (“Science Is Not Authoritarian”) Science Is a Complex Social Activity Science Is a Complex Social Activity Science Is Organized Into Content Disciplines Science Is Organized Into Content Disciplines and Is Conducted in Various Institutions and Is Conducted in Various Institutions There Are Generally Accepted Ethical There Are Generally Accepted Ethical Principles in the Conduct of Science Principles in the Conduct of Science Scientists Participate in Public Affairs Both as Scientists Participate in Public Affairs Both as Specialists and as Citizens Specialists and as Citizens …Aspects of the “Nature of Science” Adapted from Science for All Americans (link) link and Benchmarks for Science Literacy (link) link

What lessons can be learned from these activities that would help students get a better understanding of the “nature of science” (NOS)? The Rope Trick The Human Tangle Activities: Why should activities such as these be more likely to increase student understanding and achievement than other alternatives? The Oxygen Machine