Research final Flashcards
experimental research
based on logical structure or design
inferences about cause and effect
designed to control for confounding variables
extraneous variables
an factor not related to purpose of the study which may affect dependent variables
when uncontrolled, become confounding variables
true experimental designs (essential 3)
independent variable manipulated by experimenter
include control or comparison group
random assignment
random assignment
each participant has equal chance of being assigned to any group
helps control for extraneous variables and prognostic indictors
simple random assignment
equal chance of either group
may have unequal groups
block random assignment
divided equally into blocks
stratified random assignment
when certain attributes may be confounding
cluster random assignment
each cluster randomly assigned a treatment
all members of a cluster get same treatment
concealed allocation
when a participant is determined to be eligible, researchers do not know group assignment
statistical conclusion validity
is there a relationship between IV and DV?
internal validity (3 components)
is evidence of a casual relationship between IV and DP
temporal precedence
covariation of cause and effect
no plausible alternative explanation
construct validity
to what constructs can results be generalized
external validity
can results be generalized to other persons, settings, or times
order of experimental design validity
statistical conclusion validity
internal validity
construct validity
external validity
internal threats
history
maturation
attrition
testing
instrumentation
regression to mean
selection
social interaction
internal validity: social threats
diffusion/imitation - imitate experimental group
compensatory equalization - treat control differently
compensatory rivalry - control works extra hard
demoralization - control gives up
ruling out threats to internal validity
random assignment
blinding
threats to construct validity
operational definitions
comprehensive measurements
time frame
multiple treatment interactions
threats to external validity
influence of selection
influence of settings
influence of history
noncompliance
refuse assigned treatment after allocation
cross over to another group
withdraw from study
missing data
need to account
concerning if >20%
especially if related to treatment
per protocol analysis
analyze only who complete
intention to treat analysis
analyze with the group they were assigned to
quasi-experimental
may lack randomization
may lack comparison group
may lack both