The
Scientific Method
Psychologists use the
scientific method to conduct their research. The scientific method is
a standardized way of making observations, gathering data, forming theories,
testing predictions, and interpreting results.
Researchers make
observations in order to describe and measure behavior. After observing certain
events repeatedly, researchers come up with a theory that explains these
observations. A theory is an explanation that organizes
separate pieces of information in a coherent way. Researchers generally develop
a theory only after they have collected a lot of evidence and made sure their
research results can be reproduced by others.
Example: A
psychologist observes that some college sophomores date a lot, while others do
not. He observes that some sophomores have blond hair, while others have brown
hair. He also observes that in most sophomore couples at least one person has
brown hair. In addition, he notices that most of his brown-haired friends date
regularly, but his blond friends don’t date much at all. He explains these
observations by theorizing that brown-haired sophomores are more likely to date
than those who have blond hair. Based on this theory, he develops a hypothesis
that more brown-haired sophomores than blond sophomores will make dates with
people they meet at a party. He then conducts an experiment to test his
hypothesis. In his experiment, he has twenty people go to a party, ten with
blond hair and ten with brown hair. He makes observations and gathers data by
watching what happens at the party and counting how many people of each hair
color actually make dates. If, contrary to his hypothesis, the blond-haired
people make more dates, he’ll have to think about why this occurred and revise
his theory and hypothesis. If the data he collects from further experiments
still do not support the hypothesis, he’ll have to reject his theory.
Making
Research Scientific
Psychological research,
like research in other fields, must meet certain criteria in order to be
considered scientific. Research must be:
·
Replicable
·
Falsifiable
·
Precise
·
Parsimonious
Research
Must Be Replicable
Research is replicable when
others can repeat it and get the same results. When psychologists report what
they have found through their research, they also describe in detail how they
made their discoveries. This way, other psychologists can repeat the research
to see if they can replicate the findings.
After psychologists do
their research and make sure it’s replicable, they develop a theory and
translate the theory into a precise hypothesis. A hypothesis is
a testable prediction of what will happen given a certain set of conditions.
Psychologists test a hypothesis by using a specific research method, such asnaturalistic
observation, a case study, a survey, or an experiment.
If the test does not confirm the hypothesis, the psychologist revises or
rejects the original theory.
A Good Theory
A good theory must do two
things: organize many observations in a logical way and allow researchers to
come up with clear predictions to check the theory.
Research
Must Be Falsifiable
A good theory or hypothesis
also must be falsifiable, which means that it must be stated in a
way that makes it possible to reject it. In other words, we have to be able to
prove a theory or hypothesis wrong. Theories and hypotheses need to be
falsifiable because all researchers can succumb to the confirmation bias.
Researchers who display confirmation bias look for and accept
evidence that supports what they want to believe and ignore or reject evidence
that refutes their beliefs.
Example: Some
people theorize that the Loch Ness Monster not only exists but has become
intelligent enough to elude detection by hiding in undiscovered, undetectable,
underwater caves. This theory is not falsifiable. Researchers can never find
these undiscovered caves or the monster that supposedly hides in them, and they
have no way to prove this theory wrong.
Research
Must Be Precise
By stating hypotheses
precisely, psychologists ensure that they can replicate their own and others’
research. To make hypotheses more precise, psychologists use operational
definitions to define the variables they study. Operational definitionsstate
exactly how a variable will be measured.
Example: A
psychologist conducts an experiment to find out whether toddlers are happier in
warm weather or cool weather. She needs to have an operational definition of
happiness so that she can measure precisely how happy the toddlers are. She
might operationally define happiness as “the number of smiles per hour.”
Research
Must Be Parsimonious
The principle of
parsimony, also called Occam’s razor, maintains that
researchers should apply the simplest explanation possible to any set of
observations. For instance, psychologists try to explain results by using
well-accepted theories instead of elaborate new hypotheses. Parsimony prevents
psychologists from inventing and pursuing outlandish theories.
Parsimony
Parsimonious means
“being thrifty or stingy.” A person who values parsimony will apply the
thriftiest or most logically economical explanation for a set of phenomena.
Example: Suppose
a student consistently falls asleep in her statistics class. She theorizes that
before each class, her statistics professor secretly sprays her seat with a
nerve gas that makes her very drowsy. If she had applied the principle of
parsimony, she would not have come up with this theory. She can account for her
sleepiness with a much simpler and more likely explanation: she finds statistics
boring.
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