The history of science education and nature of science

The History of Science Education and Nature of Science Dr. Jeanelle Day

Origins of Inquiry-Oriented Instruction • Use of laboratory unheard of until mid-1800’s. Physical materials and specimens, though rarely used, served to verify lectures/book information. • By mid-late 1800’s, labs were extremely popular as they were believed to be useful in “disciplining” the mind. • Mental “discipline” came from popular psychological theory that – Human mental behavior was compartmentalized (logic, memorization, observation) – Such mental behavior could be enhanced by exercising these faculties – These faculties, when developed, would function in all life situations. • Theory was used to justify the use of abstract, meaningless, laborious tasks during instruction to “exercise and strengthen” the mind!

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As this theory lost favor among psychologists, the emphasis in schools shifted away from rote tasks and toward an effort to present meaningful information, develop positive attitudes and interests in science, and develop useful reasoning skills. By 1898, the NEA made the following recommendation: – “The high school work should confine itself to the elements of the subject…full illustration of principles, and methods of thought.”

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The 1910 report by the Central Association of Science and Mathematics Teachers suggested: – More emphasis on “reasoning out” than memorization. – More emphasis on developing a problem-raising and problemsolving attitude among students. – More applications of the subject matter to personal and social issues. – Less coverage of territory; the course should progress no faster than students can go with understanding. • Yet no methods of how to accomplish this were suggested!

Origins of Inquiry-Oriented Instruction •

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In 1916, John Dewey addressed the NEA and argued that “science is primarily the method of intelligence at work in observation, in inquiry and experimental testing; that, fundamentally, what science means and stands for is simply the best ways yet found out by which human intelligence can do the work it should do, ways that are continuously improved by the very process of use.” As an instructional method, Dewey suggested a series of events called a complete act of thought. 1. 2. 3. 4. 5.

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Sensing the problem or question. Analyzing the problem. Collecting evidence. Interpreting the evidence. Drawing and applying conclusions.

It would take another 40 years before this view of the Nature of Science would make its way into large-scale science curriculum movements, or not until the NSF sponsored curriculum development projects in the late 1950’s and early 1960’s as a response to Sputnik.

In the 30 years between 1952 and 1982, there was a shift in society towards a dependence on technology and science.

• In 1952, production of technology was important. • In 1982, the major concern became educating all citizens to participate in the highly technological world produced by the previous generation.

Today, we have a richer understanding about the processes associated with the growth of knowledge. Shapere (1984) discovered three things about the nature of science. 1. The standards used to assess the adequacy of scientific theories and explanations can change from one generation of scientists to another. 2. The standards used to judge theories at one time are not better or more correct than standards used at another time. 3. The standards used to assess scientific explanations are closely linked to the then-current beliefs of the scientific community.

Themes of Science • Science as a way of thinking – Beliefs, curiosity, imagination, reasoning, cause and effect relationships, and self-examination and skepticism, objectivity and open-mindedness.

• Science as a way of investigating – Hypothesis, observation, experimentation, mathematics (i.e. Bacon’s “Mathematics is the door and the key to science).

• Science as a body of knowledge – Facts (directly observable & can be demonstrated at any time), concepts (name, definition, attributes, values, examples), laws and principles (examples of concepts), theories (explain underlying patterns and forces and never become fact or law), models (no distinctions between models, hypotheses, and theories

• Science and its interactions with technology and society. – Each influences the other.

Scientific theories are often confused with scientific fact. It is important for teachers to understand that: • All scientific explanations are not equal; some ideas are more important than others. • A scientific explanation can rise and fall from grace in the scientific community. • Criteria exist for judging or evaluating scientific explanations. • A description of the rational evolution of scientific explanations is possible.

It is important to remember that knowledge about science and scientific knowledge are two different things. • Knowledge about science is knowledge of both why science believes what is does and how science has come to think that way. – In a curriculum that relies on this idea, interactions among science, technology, and society are more relevant.

On the other hand, • Scientific knowledge claims--facts, hypotheses, principles, theories--are learned on the basis of their contribution to the final form models of knowledge. – How knowledge came to exist is not an issue in this form of curriculum.

The Nature of Science • In the NSES, NOS is divided into three categories: – The Scientific World View – Scientific Inquiry – The Scientific Enterprise

Learning in science and cognitive development in general are conceived as processes in which old ideas, concepts, and meanings are replaced by new ones. • “Cognitive development is a process involving conceptual changes. The challenge for science teachers is how to design instructional strategies that will promote the evolution of students’ naive views into the more sophisticated scientists’ views” - Carey (1985)

Conceptual change teaching model is different from other models of teaching science because there is the recognition that all learning begins with and is subsequently influenced by the prior knowledge of the student. • Hanson (1958) put it this way: “What we see is determined by what we know.”

Theories tend to determine what we observe.

There are two faces of science: • Science as a process of justifying knowledge-what we know. • Science as a process of discovering knowledge--how we know.

In large part, students are bombarded with tasks that teach what is known by science without learning about the discovery process of science. Teaching the “what” without teaching about the “how” runs the risk of making science instruction incomplete. Kilborn (1980) suggests that all too often, science instruction is taken out of context and presented without the critical background material necessary for an understanding of the meanings or transitions of science.

If teachers do not fill in the gaps for students, they will fill them in themselves, more often than not, with ideas and self-constructed theories that are incorrect and lead to less success in science at higher grade levels. This makes science inaccessible to many young students (Novak & Gowin, 1984).

It is important to remember that facts derive meaning from theory, not vice versa. As science educators, we must convince students that change is a normal element of the growth of scientific knowledge.

When we neglect to present science as a process of revision and substitution of knowledge claims, we run the risk of: • Developing in students the perception that scientific-knowledge growth is governed by the addition of new ideas, facts, and theories to old ones; and • Portraying science as an activity in which scientists always seem to agree or have a consensus.

It is fundamental that sound instruction seeks ways to partition knowledge claims and establishes the relationship among the parts. There are six models that can be used to attempt to explain or characterize knowledge growth in science. • • • • • •

Goal-of-Science Hierarchy Levels of Theories Argument Pattern for Testing Theories Four Criteria for Theory Evaluation Triadic Network Tripartite Process of Observation

Goal-of-Science Hierarchy--places theories within a general scheme that seeks to establish explanations and understandings of the natural world.

Levels of Theories Ce nter Le v el Core Explanatio n No Competition Solid Obser v ation Base Sets Stand ards for In quiry

Cel l Theory

Per iodi city of El ements

Kine ti c Theor y of Heat

Frontie r Le ve l Estab lished Explanations Few Competitor s Good Data Base Has a Few Unexplained Elements

Pl ate Tec toni cs

Evol uti on

Quark Physi cs

Fringe Lev el New Expla nations Crank Idea s Grand Speculations M any Competito rs

Sci entific Crea ti onism

Extinc ti on of Dinos aurs by Meteori te Coll is ion

Fi fth Fundamental Forc e

Argument Pattern for Testing Theories (Giere, 1984) *The theory is treated as a hypothesis in which a theoretical model is making a claim about the real world. This is a “Theoretical Hypothesis”. *The hypothesis is then treated as both a contingent statement (either it is true or false) and a conclusion of an argument. *The argument is a set of premises that lead to a statement of a conclusion. * An argument is analyzed by testing the truthfulness of the premises (all must be true), or by testing the internal consistency of the set of true premises (there can be no contradictions).

Four Criteria for Theory Evaluation (Root-Bernstein, 1984): 1. Logical criteria-good theories provide sound explanations, and sound explanations are based on logically sound arguments; 2. Empirical criteria-valid but unexplained data or empirical facts are referred to as anomalous data and are important in changing the explanations of science. When enough data exists, some scientists question existing central theories. 3. Sociological criteria-science does not function in isolation, and scientists do not practice their profession without influence from the outside. 4. Historical criteria- ensures the growth of scientific knowledge has followed a path that clearly establishes correctability.

Triadic Network of Justification Methods Methods JUSTIFY Theories/ Theories CONSTRAIN Methods

The ories

Aims JUSTIFY Metods/ Methods EXHIBIT REALIZABILITY in Aims

Must Harmonize

Aims

Tripartite Process of Observation (Shapere, 1984) • The release of information by a source • The process of transmitting the information • The reception of information – A large part of what we seek to accomplish in the science classroom is moving students from novice “seeing as” observers or naive “seeing that” observers to informed “seeing that” observers.

Now look at the handout entitled “Essential Concepts to be Covered in the Study of Evolution” Do the textbooks you have used either in class or to teach cover all of these topics?

Essential Concepts to Be Covered in Teaching Evolution • • • • • • • • • •

Dating the earth The Big Bang Fossils of different ages Comparative anatomy Embryonic development Comparative genetics Comparative physiology Geographic distribution Classification of species Experimental manipulation of populations under controlled conditions