hindsight bias
The tendency to believe, after learning an outcome, that one would have foreseen it.
replication
Repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding can be reproduced.
sampling bias
A flawed sampling process produces an unrepresentative sample.
random sample
A sample that fairly represents a population because each member has an equal chance of inclusion
random assignment
Assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between different groups.
confounding variables
Other factors that can potentially influence a study’s results.
skewed distribution
A representation of scores that lack symmetry around their average value.
illusory correlation
Perceiving a relationship where none exists, or perceiving a stronger-than-actual relationship.
validity
The extent to which a test or experiment measures or predicts what it is supposed to
reliability
The extent to which a test yields consistent results, as assessed by the consistency of scores on two halves of the test, on alternative forms of the test, or on retesting
case study
study one individual in great depth
survey
asking people to report on their behavior and/or opinions
naturalistic observation
describing observed behavior
descriptive research method
to observe and record behavior
correlational research method
to detect naturally occurring relationships; to asses how well one variable predicts another
experimental research method
to explore cause and effect
double-blind procedure
neither the subject nor the experimenter should know who was assigned to each group
random assignment
subjects should be randomly assigned by chance to the different groups
positive correlation
when one variable goes up, so does the other (closer to +1.0)
negative correlation
when one variable goes up, the other goes down (closer to -1.0)
no correlation
no clear relationship indicated
standard deviation
a measure of how far a score differs from the mean (the larger the standard deviation, the more the scores are dispersed)
range
the gap between the highest and lowest score