The Nature of Science

The Nature of Science

Introduction

Science is a way of knowing, describing, classifying, and understanding the universe. Scientific literacy requires engagement in discourses about science and understanding the nature of science (NOS), including its strengths and limitations which is crucial in a "Science for All" curriculum. Other ways of knowing include aesthetic, interpersonal, intuitive, narrative, formal, and practical modes. Awareness of these various ways of knowing allows appreciation of the role of scientific knowing within a broader perspective.

NOS is defined as the values and assumptions inherent to science (Lederman, 1992, p. 331). The discipline of science is committed to evidence as the basis of justified belief about material causes and the rational means of resolving controversy (Siegel, 1989). Science is also progressive and universal (Good & Shymansky, 2001). However, opinions on NOS differ among scientists, philosophers, and science educators (Fourez, 1989; Lederman, 1986; Meichtry, 1993). A pragmatic approach is adopted for school science.

Some features of NOS, such as creativity and the presence of competing explanations/theories, are also features of other ways of knowing. Features of NOS are presented in two parts: distinguishing and non-distinguishing features (Smith & Scharmann, 1999).

Features of the Nature of Science

Distinguishing Features:

1. Empirical Evidence:
   • Scientific knowledge needs empirical evidence, derived from observation or experiment.
2. Testability/Falsifiability:
   • Scientific claims must be testable/falsifiable. Karl Popper (1968) suggested that only falsifiable ideas are scientific. Creation science is an oxymoron because the notion of fully-formed species placed on Earth by supernatural force is a religious belief which is not testable/falsifiable.
3. Repeatability:
   • Scientific tests or observations must be repeatable.
4. Tentative and Developmental:
   • Scientific knowledge is tentative, developmental, and fallible. Different degrees of tentativeness are associated with different types of scientific knowledge. Examples:
     • Certain: Boyle’s law, copper as a good conductor of electricity, Earth being round.
     • Less Certain: Origins of modern man, asteroid causing mass extinction of dinosaurs, no life on Mars.
5. Self-Correcting:
   • Science is self-correcting.

Non-Distinguishing Features:

6. Competition Among Hypotheses/Theories:
   • Scientific progress involves invention of, and competition among, hypotheses/theories. Example:
     • Wegener’s continental drift theory was initially considered lunatic.
     • Rutherford and Thomson disputed atomic models despite similar results for alpha particle scattering.
7. Differing Interpretations:
   • Different scientists can sense the same things and interpret experimental data differently. Observations are theory-laden. Example:
     • Millikan discarded 59\% of oil drop results that didn't support his hypothesis of elementary charge.
     • Ehrenhaft obtained similar results and postulated fractional electronic charges.
8. Incomplete Answers:
   • Science cannot provide complete answers to all questions/problems. It answers many questions very well but cannot answer moral, ethical, aesthetic, social, and metaphysical questions. Science can however provide useful insights to them. Asking science to determine the acceptability of abortion is inappropriate.
9. Social Activity:
   • Science is a social activity, influencing and being influenced by society. Personalities, funding, social movements, public opinion, media, and politicians drive science.
10. Role of Logic, Imagination, Curiosity, and Serendipity:
    • Logic, imagination, curiosity, and serendipity contribute to scientific exploration.

Some Myths

Myth 1: A Universal Scientific Method Exists

This myth stems from the series of sequential steps, commonly termed the scientific method, which appear in many school texts and is reinforced by the standardised format used to present articles in science journals. The steps vary from text to text, but typical steps include:

• Observing
• Forming a hypothesis
• Testing the hypothesis
• Reaching a conclusion/s
• Reporting the work

Scientists use a multiplicity of ways to obtain and organise knowledge, including intuition and chance rather than working to a standard research plan. Newer texts are adopting the approach of discussing the methods of science, rather than any particular scientific method alone, and this will assist in overcoming this myth. At the same time, though, the above steps do appear in the history of most scientific work, even if their order is found to vary.

Myth 2: A Hypothesis Is an Educated Guess

Terms associated with the progress of science:

• Law (or rule or principle) – a generalised statement which summarises the observed regularities or patterns in nature (e.g. Charles’ law and Archimedes’ principle).
• Hypothesis – a possible explanation for the observed facts and laws (e.g. Bohr’s hypothesis).
• Theory – an explanation, which has stood the test of time and in which we therefore show much faith (e.g. the kinetic theory of gases and the atomic theory). A theory may be a broad explanation derived from the convergence of many hypotheses.
• Model – a mental picture of, or analogy for, the phenomenon, involving a system which is well understood and which appears to behave in a similar manner to the system under consideration (e.g. the particle model of a gas).
• Test hypothesis (or test theory) – accomplished by determining whether or not the hypothesis, or theory, is in accord with new experimental evidence. Experiments are purposely designed to test a prediction of a hypothesis or theory. The new experimental evidence is said to either support or refute the hypothesis or theory. If refuted, the hypothesis or theory may be either modified or abandoned completely. A hypothesis or theory can never be proven absolutely correct, because subsequent evidence could always refute it.

When school students are asked to propose a hypothesis during experimental work, they are really most often being asked for a prediction, which is different. A prediction is an educated guess about the expected outcome of a test and is likely to be factual, and most predictions can be evaluated by observation. Hypotheses, on the other hand, are possible reasons/explanations for the observations, being stated in a manner that makes them amenable to testing and falsification.

Myth 3: Hypotheses Become Theories, Which in Turn Become Laws

A hypothesis might become a theory, but laws and theories are different kinds of knowledge. Laws summarise regularities or patterns in nature, while theories attempt to explain these generalities. For example, we have the law of universal gravitation, but presently we do not have a well-accepted theory of gravity.

Myth 4: Science Is a Solitary Pursuit

Contrary to common portrayal in texts, scientific ideas rarely arise in the mind of an individual who then also validates the idea before the scientific community accepts it. Instead, scientists work in teams, and scientific ideas arise from negotiation. Today, 95\% of biology research reports are multiauthored, compared with 5\% a century ago. The awarding of Nobel prizes to individuals, rather than research teams, may be reinforcing this myth.

Pedagogical Considerations

It is unrealistic to expect students to automatically come to an understanding of NOS simply by being involved in enquiry activities (Abell, Martini, & George, 2001; McComas, 1998). There is a need to address NOS explicitly (Moss et al., 2001). This might be achieved by linking aspects of student activities to NOS, by using specific learning experiences which address NOS, and by including in science courses stories or case studies about discoveries, the lives of scientists, and controversies. There is relatively little in the way of strategies to facilitate student learning about NOS. Such learning experiences may be found in SER.