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The Scientific Method

There are many ways to obtain knowledge. Modern sci￾entists tend to obtain knowledge about the world by

making systematic observations. This principle is called

empiricism and is the basis of the scientific method. The

scientific method is a set of rules for asking and answer￾ing questions about science. Most scientists use the

scientific method loosely and often unconsciously.

However, the key concepts of the scientific method are

the groundwork for scientific study, and we will review

those concepts in this section.

The scientific method involves:

■ asking a specific question about a process or phe￾nomenon that can be answered by performing

experiments

■ formulating a testable hypothesis based on obser￾vations and previous results

■ designing an experiment, with a control, to test

the hypothesis

■ collecting and analyzing the results of the

experiment

■ developing a model or theory that explains the

phenomenon and is consistent with experimental

results

■ making predictions based on the model or theory

in order to test it and designing experiments that

could disprove the proposed theory

THE QUESTION

In order to understand something, a scientist must first

focus on a specific question or aspect of a problem. In

order to do that, the scientist has to clearly formulate the

question. The answer to such a question has to exist and

the possibility of obtaining it through experiment must

exist. For example, the question “Does the presence of

the moon shorten the life span of ducks on Earth?” is not

valid because it can not be answered through experi￾ment. There is no way to measure the life span of ducks on

Earth in the absence of the moon, since we have no way of

removing the moon from its orbit. Similarly, asking a

general question, such as “How do animals obtain food?”

is not very useful for gaining knowledge. This question is

too general and broad for one person to answer.

Better questions are more specific—for example,

“Does each member of a wolf pack have a set responsi￾bility or job when hunting for food?” A question that is

too general and not very useful is “Why do some people

have better memories than others?” A better, more spe￾cific question, along the same lines, is “What parts of the

brain and which brain chemicals are involved in recol￾lection of childhood memories?”

A good science question is very specific and

can be answered by performing experiments.

THE HYPOTHESIS

After formulating a question, a scientist gathers the

information on the topic that is already available or pub￾lished, and then comes up with an educated guess or a

tentative explanation about the answer to the question.

Such an educated guess about a natural process or phe￾nomenon is called a hypothesis.

A hypothesis doesn’t have to be correct, but it should

be testable. In other words, a testable hypothesis can be

disproved through experiment, in a reasonable amount

of time, with the resources available. For example, the

statement, “Everyone has a soul mate somewhere in the

world,” is not a valid hypothesis. First, the term soul mate

is not well defined, so formulating an experiment to

determine whether two people are soul mates would be

difficult. More importantly, even if we were to agree on

what soul mate means and how to experimentally deter￾mine whether two people are soul mates, this hypothe￾sis could never be proved wrong. Any experiment

conceived would require testing every possible pair of

human beings around the world, which, considering the

population and the population growth per second, is just

not feasible.

A hypothesis doesn’t need to be correct. It only

has to be testable.

Disproving a hypothesis is not a failure. It casts away

illusions about what was previously thought to be true,

and can cause a great advance, a thought in another

direction that can bring about new ideas. Most likely, in

the process of showing that one hypothesis is wrong, a

–SCIENCE AS INQUIRY–

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