exam 4 Flashcards
quasi experiments
use real-life settings to examine the effects of treatments
lack full control over variables
has manipulation but not a true manipulation
pros of QE
real world opportunties- applied research
legislative impacts
enchances external validity
ethics
cons of QE
threats to internal validity
types of QE
natural( nonequivalent) group studies- occurs naturally
non equivalent- post test only or pre and post test
interuppted time series- measures DV 2+ times
interrupted time series w/ non equiv control-many measurements
what threats occur in indepdent-groups design in QE
selection effects
potential lack of equivalence between groups
there is no randomization or pretest to help determine equivalence
threats to IV in pre-post test designs for QE
selection effects
maturation threat-not clear whether the change would have happened w/o treatment
other threats to IV fro QE
selection effects
history
maturation
mortality
regression to mean
testing/instrumentation
observer bias
placebo effect
time series designs
post test
repeated measures (pre and post)
interrupted time series
factorial designs
complex studies w. more than 1 IV
pros of factorials
capture real-life causal complexity
answer mulitple questions in one experiement (main effects and interactions)
efficiency
easier to examine individual differecnes
good for therapy evaluations
main effects
when an IV had an overall effect on a DV
interactions
when the way in which an IV influences a DV depends on the level of another IV
types of factorial designs
between subjects
within subjects
mixed-factorial desisgn
mixed facotrial
manipulation of 1 IV between subjects and 1 within
non-maniuplated IV facotrial
a researcher measures it but doesn’t manipulate it
usually participant variables
now it is not an experiemnt
within factorial
all IVs are manipuated- controls for extraneous particpant variables and quicker
between factorial
all of the IVS are manipulated
avoids carryover effects
interaction effect
the effect of 1 IV depends on the level of another
ex: friend asks u to movies, you say “depends on who’s going and what movie it is”
spreading interaction
effect of IV can depend on the level of the other
either a weak effect or no effect of that Iv at the other level of the other IVS
cross-over interaction
an IV has an effect at both levels of the OV but effects are in opposite directions
simple effects
an interaction simply informs us that the effects of at least 1 IV depends on the level of another IV
breaking down the interaction
