The Method of Natural Science
By Steve Badger, PhD
Introduction
As you consider the description of the scientific
method (SM) below, you should know that not everyone agrees that there is a single SM.
Most practitioners of the natural sciences, however, would probably agree, with perhaps
some slight variations, with this description. On the other hand, philosophers generally
assert that defining science and describing the SM are not tasks for scientists at all,
but are more properly philosophical questions. To repeat this thought
using different words, when a scientist attempts to define science,
he/she is doing philosophy.
Some have described science as a body of knowledge (the information in
science textbooks is science). Others have defined it as what scientists do (that is,
follow scientists around and note what they do; what they do is science). Still others
take a historical view (what recognized scientists have studied through the last few
centuries is science).
But before natural science is any of these, it is a method of answering
questions, of solving problems, of discovering, of finding out. The SM uses only data
gathered via the physical senses and our instrumental extensions of these senses (like a
microscope or telescope). Thus, the SM is empirical.
Though not as rigid as the outline below might suggest, the method used in the natural
sciences typically conforms to the following pattern (with occasional minor variations in
sequence). Observation (including all five senses) is overarching
and is assumed in all of the steps below.
An outline of the scientific method
The researcher using a SM will usually follow this pattern:
1. On the basis of having observed everything related to the
problem/question, formally state the problem to be solved/the question to be answered.
This provides focus.
2. Find out what is already known about the problem/question. Typically this involves a
search of the scientific literature.
3. Using what data are available, form a hypothesis, a
tentative explanation that seems to fit everything known about the problem/question to
this point.
4. Construct univariate, controlled experiments to try to test the hypothesis.
5. The observed results of the experiment will provoke the researcher
to. . .
- A. Continue testing the hypothesis as it is...OR...
- B. Modify the hypothesis and continue testing it...OR...
- C. Discard the hypothesis and form a new one to be tested.
In each case, the researcher using the SM cycles between #4 and #5...until...
6. At some point the body of evidence supporting the hypothesis may become so great
that we re-label it theory. (What is the difference between a
hypothesis and a theory?)
7. Construct univariate, controlled experiments to try to test the theory.
8. The observed results of the experiment will provoke the researcher
to. . .
- A. Continue testing the theory as it is...OR...
- B. Modify the theory and continue testing it...OR...
- C. Discard the theory and form a new one to be tested.
In each case, the researcher using the SM cycles between #7 and #8...until...
9. At some point the body of evidence supporting the theory may become so great that it
is acknowledged to be universally true. At this point, we re-label it scientific
law or (in biology) a principle. (Note:
hypothesis > theory > law/principle)
Foundations of the scientific method
Many people mistakenly think that scientists approach their problem
solving/question answering work with no assumptions. But in fact scientists, like all
people, take several assumptions to their work.
First, consider these presuppositions that are basic to all knowledge:
- I exist.
- Other people exist.
- Reciprocal communication can take place between people.
- The external world (including nature) exists independent of the mind.
Then, these assumptions are fundamental to the SM:
- Nature is real, not an illusion.
- Nature is understandable and knowable by our observations of it.
(That is, our physical senses provide reliable data about the physical world.)
- Nature is orderly and uniform.
- Natural laws are not affected by time.
- Measurement yields knowledge of the thing measured.
These lists are representative, not complete (adapted from Dallas Roark's Introduction
to Philosophy).
Limitations of the SM and Its Practitioners
The SM is not able to discover all truth. The method has limitations,
but beyond that, its practitioners do not always use it correctly. With this in mind,
consider these strengths and weaknesses.
| Strengths1. The SM excludes speculation that has no empirical basis.
2. The SM holds most conclusions as tentative.
3. The SM tends to be self-correcting (though not necessarily short-term).
4. The SM promotes objectivity and discourages subjectivity.
5. One answer/solution tends to suggest other questions/problems to be studied.
6. Results are typically published in peer-reviewed journals allowing others
knowledgeable in the field to evaluate their work.
7. Conclusions that cannot be duplicated and verified by independent investigators are
discarded.
8. The SM has an unrivaled "track record." |
Weaknesses/limitations1. The SM is used by people who are no more objective than folks in other
disciplines.
2. Scientists tend to be reductionistic, reducing a phenomenon to its simplest
description.
3. Scientists pretend they make observations with no prior assumptions or
presuppositions.
4. Scientists often present preliminary findings before they are confident of their
validity.
5. Scientists think the SM is the only method of gaining knowledge.
6. The SM itself lacks a generally accepted definition.
7. The SM limits the search for reality to the physical (i.e., it excludes the
spiritual).
8. The SM cannot address ethical questions (is an action wrong?); thus the SM is
amoral. |
Scientific attitudes
- Observation (which includes all five physical senses) should be the controlling factor.
- Hypotheses and theories should be held loosely and modified or discarded as contrary
data is found.
- A single experiment may disprove a hypothesis/theory, but should not be thought of as
proving it; the results of an experiment merely support a hypothesis/theory.
- The researcher must honestly report all observations, not just those that seem to
support a favored theory.
(Note: scientists do not always display all of these attitudes.)
What makes a discipline "science"?
Those disciplines that use the method described above (or some minor
variation) are considered science. Those that don't, are not. (Two notes: 1. this is a
generalization; 2. by "science" I mean "natural science.")
A field of study is not increased in value by labeling it "science." An area
of investigation is not debased by labeling it "non-science."
To further complicate the answer to this question, some disciplines are part science,
part non-science. (Can you name some?)
What makes a statement or a question
"scientific"?
Generally, a statement or question is considered scientific if and only
if it can be tested by the scientific method—at least in principle.
For example, consider this statement: "Matter is ultimately made up of particles
so small that we will never be able to discover them." Sounds good, right? But can it
be tested (even in principle)? No. Thus it is not scientific. On the other hand,
"Jupiter is composed of whipped cream and cottage cheese" sounds dumb. But, it
can be tested; so it is scientific.
Can you identify some other statements or questions that are often addressed by
scientists that are technically not scientific questions? Can the SM answer all
questions/solve all problems?
Terms:
| Empirical – based on observation or
experience Experiment -- an attempt to reconstruct a situation/problem/question
Controlled experiment -- has a duplicate treated identically except for the parameter
being tested
Hypothesis – a tentative explanation that fits what is already known
Theory -- a hypothesis with much supporting data
Law -- has so much supporting data, it's accepted as universal; also called
"scientific principle," but not a "fact"; it was a fact before we knew
it was a law
Model -- an imitation of the real thing; often mathematical, diagrammatic, or computer;
e.g., atomic models, molecular models, car models, etc. |
Observation – data collected through the
physical senses or instrumental extensions of those senses (e.g., microscope, telescope) Objective
– the conclusion does not depends on the person making the observation
Subjective – the conclusion depends on the person making the observation
Phenomenon – an observable event
Science – a particular method of gaining knowledge
Technology – uses the principles gained by science to build something that uses
that principle
Univariate -- having only a single variable;
everything else is held constant |
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