Methodology Definitions
Methodology Definitions
- true experiment
- a design in which participants are assigned randomly to
treatments
- quasi-experiment
- a design that resembles that of an experiment in that discrete
groups are used, but participants are not randomly assigned to treatments nor are treatments
randomly determined for the groups.
- construct variable
- a theoretical variable that has 'reality status' such as competition, attractiveness, negative mood.
- operational variable
- the researchers' precise operational definition (i.e.,
measurement) of a theoretical construct.
- independent variable
- the variable presumed to cause a change in the dependent
variable.
- dependent variable
- the variable presumed to be affected by the independent
variable.
- matching variable
- an objective, quantifiable measure to help assure pretreatment
equivalence among groups.
- confounding variable
- a variable that systematically varies along with the
independent variable
- hypothesis
- a statement positing a relation between constructs
- theory
- a statement of a proposed relation among two or more constructs
- construct validity
- the degree to which the operational definition accurately
measures the construct of interest
- internal validity
- the extent to which causal conclusions can be drawn (i.e., the
IV effects the DV)
- external validity
- the extent to which the results generalize to the population of
interest
- face validity
- the extent to which measures seem to reflect the construct of
interest
- convergent validity
- overlap among variables presumed to measure the same
construct
- discriminant validity
- failure to find overlap among variables presumed to
measure the same construct
- subject variables
- nonmanipulated qualities of the participant sometitmes treated
as if they are true independent variables (which are manipulated and therefore their causal
nature can be assessed)
- random assignment
- the process by which subjects receive an equal chance of
being assigned to a particular condition
- manipulation check
- a measured variable designed to assess whether the
manipulation worked and tapped the desired construct
- demand characteristic
- aspect of the experiment encouraging the participant to
respond according to situational constraints
- subject expectancies
- a demand characteristic whereby subjects think they know
experimenters' interests and act accordingly.
- reliability
- the extent to which a construct is measured without error
- double-blind
- a procedure in which neither experimenter nor participant knows to
which condition the participant are assigned
- order effects
- the effects on behavior of presenting two or more treatments to the
same participants
- counterbalancing
- a technique for controlling order effects by which each
condition is presented first to each participant an equal number of times, and each condition
occurs an equal number of times at each session.
- control group
- condition which received a zero level of the construct of
interest
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