Ch 11 Flashcards
Quasi experiment design
Hybrid between true and field experiment
Types of quasi experiment designs
One group designs
Noneqivalent control group designs
Single case experimental designs
Also called single subject designs.
An experiment in which the effect of the independent variable is assessed using data from a single participant
Baseline
In a single case design, the subject later behavior during a control period before the introduction of the experimental manipulation
Reversal design
Called ABA design and requires observation
A(baseline period)>B(treatment period)>A(baseline period)
Sometimes call d withdrawal design
Multiple baseline designs
Effectiveness we of treatment is demonstrated when a behavior changes only after the manipulation is introduced.
Change must be observed in multiple circumstances to rule out the possibility that other events were responsible
Used when long lasting change in behavior is not reversible
Across subjects
The behavior of several subjects is measured over time, for each subject; manipulation is introduced at a different point in time
Across behaviors
Several different behaviors of a single subject are measured over time
At different times, the same manipulation is applied to each of the behaviors
Across situations
The same behavior is measured in different settings such as home and work
Manipulation is introduced at a different time in each setting
Variations of multiple baseline design
Across subjects
Across behaviors
Across situations
Quasi experimental designs allow..
the need to study the effect of an independent variable in settings in which the control features of true experimental design can not be achieved
Where are quasi experiment designs most likely to occur
School, business, hospital, or entire city or state
Pre experimental quasi experimental designs
One group post test only design
One group pre test post test only design
Participants>sit n cat to stranger>measure time until stranger leaves
Is an example of
On group post test only design (a quasi experiment design)
Participants>smoking measure>training program>smoking measure
Is an example of
One group pre test post test design
History effects
An T that occurs at the same time as the experimental manipulation
Is a confounding variable
Maturation effects
Any changes that occur systematically over time
Testing effects
A threat to internal validity in which taking a pretest changes behavior without any effect on the independent variable
Can happen after pre test
Instrument decay
When changes in outcome occur during to changes in observer
Ex-become fatigue or motivation
Regression toward the mean (also called statistical regression)
Occurs whenever participants are selected because they score extremely high or low on some variable
When their scores are tested again, it may change in the direction toward the mean
Nonequalivent control group desig
Employs a separate control group but the participants in the two conditions (experiment and control group) are not equivalent
Not through random assignment
Nonequilvant control group design uses____to chose participants
Selection differences
Nonequilvent pretest post test design
A quest experimental design in which nonequivlent groups ar used but a pretest allows assessment of equivalency and pretest post test changes
Propensity score
Scores on variables combined
statistical matching technique that attempts to estimate the effect of a treatment,
Propensity score matching
When individuals in treatment and control groups are matched on propensity scores
Interpreted time series design
Effectiveness of a treatment is determined by examining a series of measurements made over an extended time period both before and after the treatment is introduced
The treatment is not random at any point
How to improve interrupted time series design
Control series design
Control series design
An extension of the interrupted time series quasi experiment design in which there is a comparison or control group
Cross sectional method
Person of different ages are studies at only one point in time
Longitudinal method
Same group of people observed at different points in time as they grow older
Cohort
A group of people born at about the same time, exposed to the same events in a society and influenced by the same demographic trends such as divorce rates and family size
Cohort effects
Differences in different cohorts depending on what they were raised with
Sequential method
A compromise between longnitinal and cross sectional methods
A combination of the cross sectional and longnitudial design to study developmental research questions
Developmental psych uses …
Cross sectional studies
Longnitudial studies
What are some problems with experimental methods
Experimenter expectancy effect (also known as rosenthal effect)
Participant expectancy (demand characteristics/placebo)
