exam 3 Flashcards
one-group pretest-posttest design
dependent variable is measured one before the treatment is implemented and one after
one-group posttest only design
a treatment is implemented (or independent variable is manipulated) and then a dependent variable is measured one after the treatment is implemented
history
other things might have happened between the pretest and posttest that caused a change from pretest to posttest
maturation
participants might have changed between the pretest and posttest in ways that they were going to anyway because they are growing and learning
testing
when the act of measuring the dependent variable during the pretest affects participants responses at posttest
threats of internal validity of the one-group pretest- posttest design
history, maturation, testing, instrumentation, regression to the mean, spontaneous remission
instrumentation
when the basic characteristics of the measuring instrument change over tie - participants might gain skill, become fatigued, etc
regression to the mean
an individual who sores extremely high/low on a variable on one occasion will tend to sore less extremely on the next occasion
spontaneous remission
a tendency for any medical and psychological problems to improve over time without any form of treatment
interrupted time-series design
a time series
like this one is “interrupted” by a treatment
time series
a set of
measurements taken at intervals over a period of time
nonequivalent groups design
is a between-subjects design in which participants have not been
randomly assigned to conditions - multiple types
posttest only nonequivalent groups design
participants in one group are exposed to a treatment, a nonequivalent group is not exposed to the treatment, and then the two groups are compared
pretest-posttest nonequivalent groups design
there is a treatment group that is given a pretest, receives a treatment, and then is given a posttest. But at the same time there is a nonequivalent control group that is given a pretest, does not receive the treatment, and then is given a posttest
interrupted time-series design with nonequivalent groups
involves taking a set of measurements at intervals over a period of time both before and after an intervention of interest in two or more nonequivalent groups
pretest-posttest design with switching replication design
nonequivalent groups are administered a pretest of the dependent variable, then one group receives a treatment while a nonequivalent control group does not receive a treatment, the dependent variable is assessed again, and then the treatment is added to the control group, and finally the dependent variable is assessed one last time
switching replication with treatment removal design
the treatment is removed from the first group when it is added to the second group.
quasi
“resembling” - this is research that resembles experimental research but is not true experimental because it lacks random assignment to conditions or orders of conditions
Quasi-experiments
are most likely to be conducted in field settings in which random assignment is difficult or impossible.
Combination design
a type of quasi-experimental design that is generally better than either the nonequivalent groups design or the pretest-posttest design because it combines elements of both.
experiment
a type of empirical study in which an independent variable is measured while extraneous variables are controlled
internal validity
the extent to which the design of a study supports the conclusion that differences in the independent variable caused any observed differences in the dependent variable
external validity
the extent to which the results of a study can be generalized to people and situations beyond those actually studied
field experiment
an experiment that is conducted outside the laboratory
manipulate
systematically changing the level of the independent variable across groups or situations
condition
one level of the independent variable in an experiment
manipulation check
a measure of an independent variable – usually done at the end of the procedure – to confirm that the independent variable was successfully manipulated
extraneous variable
any variable in the context of an experiment other than the independent and dependent variables
control
holding extraneous variables constant
confounding variable
an extraneous variable that is one that differs across the levels of the independent varoables
between subjects experiment
an experiment in which each participant is tested in one condition
random assignment
the assignment of participants to different conditions according to a random procedure
block randomization
a method of randomly assigning participants that guarantees that the condition sample sizes are equal or almost equal. a random procedure is used to assign the first k participants into k conditions and then to assign the next k participants into the k conditions and so on until all have been assigned.
treatment
an intervention intended to change people’s behavior for the better
treatment condition
a condition in a study in which participants receive some treatment of interest
control condition
a condition in a study in which participants do not receive the treatment of interest
randomized clinical trial
an experiment designed to test the effectiveness of a psychological or medical treatment
no-treatment control condition
a control condition in which participants receive no treatment whatsoever - not even a placebo
placebo
a treatment that lacks any active ingredient or element that should make it effective
placebo effect
the positive effect of a placebo
placebo control condition
a control condition in which participants receive a placebo
waitlist control condition
a control condition in which participants are put on a waitlist to receive the treatment after the study is completed
within-subjects experiment
an experiment in which each participant is tested in all conditions
carryover effect
when being tested in one condition effects participants’ behavior in later conditions
fatigue effect
a carryover effect in which participants perform worse on a task in later conditions because they have become tired or bored
practice effects
a carryover effect in which participants perform better on a task in later conditions because they have had a chance to practice
context effect
an unintended effect of the context in which a response is made. In within-subjects experiments this can be an effect of being tested in one condition on how participants perceive stimuli or interpret their task and therefore how they respond in later conditions. in survey research, this can be an effect of the surrounding items or response scale on responses to a particular item
counterbalancing
systematically varying the order of conditions across participants
subject pool
a group of people who have agreed to be contacted about opportunities to be research particcipant
experimenter expectancy effect
the effect of a researchers expectations on participants’ behavior
double-blind design
an experimental research design in which both the participants and the experimenters are unaware of which condition the participant has been assigned to
pilot test
a small sale study conducted primarily to be sure the procedure works as planned
factorial designs
experiments that include more than one independent variable
each level of one independent variable is combined with each level of the others to produce all possible combinations
between-subjects factorial design
all of the independent variables are manipulated between subjects
mixed factorial design
possible to manipulate one independent variable between subjects and another within subjects
non-manipulated independent variable
in many experiments there are at least one of these
main effect
the effect of one independent variable on the dependent variable - averaging across the levels of the other independent variable
interaction effect
when the effect of one independent variable depends on the level of the other
spreading interactions
cross-over interaction
An interaction in which one independent variable has opposite effects at different levels of another independent variable.
simple effects
a way of breaking down the interaction to figure out what is going on by examining the effect of each independent variable at each level of the other
