2. How Psychologists Do Research
What Makes Psychological Research Scientific?
Key characteristics of the ideal scientist
Precision - Scientists start out with a general theory
, an organized system of
assumptions and principles that purports to explain certain phenomena and how they
are related. From a hunch or theory, the psychological scientist derives a hypothesis
a statement that attempts to describe or explain a given behavior. A hypothesis, in
turn, leads to predictions about what will happen in a particular situation. In a
prediction, terms are given operational definitions
, which specify how the
phenomena in question are to be observed and measured.
Skepticism - Scientists do not accept ideas on faith or authority. Caution, however,
must be balanced by openness to new ideas and evidence.
Reliance on empirical evidence - An idea must be backed by empirical evidence.
Willingness to make “risky predictions” - A scientist must state an idea in such a way
that it can be refuted. This principle of falsifiability
does not mean that the idea will
be disproved, only that it could be if contrary evidence were to be discovered. A
willingness to risk disconfirmation forces the scientist to take negative evidence
seriously and to abandon mistaken hypotheses. All of us are vulnerable to
, or the tendency to look for and accept evidence that supports our
pet theories and assumptions and to ignore or reject evidence that contradicts our
Openness - Scientists must be willing to tell others where they got their ideas, how
they tested them, and what the results were so that other scientists can replicate their
studies and verify-or challenge-the findings.
Descriptive Studies: Establishing the Facts
- a group of participants that accurately represents the larger
population that the researcher is interested in
A researcher can use special selection methods to ensure that the sample contains the
same proportion of men, women, blacks, whites, poor people, rich people, Catholics,
Jews, etc. as the general population
A sample’s size is less critical than its representativeness
allow researchers to describe and predict behavior but not
necessarily to choose one explanation over competing ones
- a detailed description of a particular individual based on careful
observation or formal psychological testing
Case studies illustrate psychological principles in a way that abstract
generalizations and cold statistics never can, and they produce a more detailed
picture, however, information is often missing or hard to interpret, the observer
who writes up the case may have certain biases that influence which facts get
noticed or overlooked, and the person who is the focus of the study may have
selective or inaccurate memories.