The Scientific Method
Theory: An integrated set of principles that organizes and predicts
Hypothesis: A testable prediction often implied by a theory.
Operational Definitions: Statements (descriptions) of the
procedures used to define research variables.
Replication: Repeating the essence of a study, usually with
different participants and in different situations.
Hindsight Bias: The tendency to believe, after learning the
outcome, that you knew that was how it would turn out.
Goal of research: To describe, predict, & explain behavior.
I. Research that Describes only
Case Study: A descriptive technique in which one person is
studied in depth in the hope of revealing universal principles.
Naturalistic Observation: Observing & recording behavior
in naturally occurring situations without manipulating or
controlling the situation.
Survey: A techniques for obtaining self-reported attitudes
or behaviors of people, usually by questioning a representative,
random sample of them.
Population: All of the people in a particular
group from with a sample may be drawn.
Random Sample: A subset of people who fairly
represent the population because each person has an equal chance of
being selected. Using a random sample increase the
generalizability (external validity) of a study.
Generalizability: The extent to which results of
a study can be applied to the outside world. Also called
False Consensus Effect: The tendency to
overestimate the extent to which others share our beliefs and behaviors.
Social Desirability Bias: Tendency of subjects
to present themselves in a socially desirable light.
|II. Research the
Describes and Predicts Behavior
Correlational Research: Research that seeks to
measure the RELATIONSHIP between two variables without trying to
determine causality or manipulating either of the variables.
Scatterplot: A graphed cluster of dots, each
which represents the values of two variables. The slope of the
dots represents the direction (+ or -) of the relationship while the
amount of "scatter" suggests the strength of the correlation.
Correlation Coefficient: A statistical measure
of the extent to which two factors vary together, and thus how well
either factor predicts the other. The statistic is always between
-1.00 and +1.00.
A Positive correlation coefficient means that as one variable
increases, so does the other.
A Negative correlation coefficient means that as one variable
increases, the other decreases (i.e., an inverse relationship).
Regardless of the strength of the relationship, correlations cannot tell
us that one variable CAUSES changes in the other because:
1) Variable X could be affecting variable Y OR
variable Y could be affecting
2) Third variables could be affecting BOTH variables X
Illusory Correlation: The perception of a
relationship between two variables where none truly exists.
Differential Research: Research that involves comparing
two or more exiting groups on some variable of interest. The
groups are typically based on some pre-existing subject variable (e.g.,
gender, age, IQ, personality trait, etc.)