PSY 3-3 Flashcards
(20 cards)
Interrupted time-series design
Examine a series of observations before and after a treatment and look for a
change in behavior
Control series design (Multiple-group time-series design):
Interrupted time series design with a control group
Single-case experimental designs
NOT case studies
Traditionally used in studies of reinforcement and behavior modification.
The researcher manipulates an IV (unlike a case study)
Behavior is recorded after treatment is introduced
Reversal design
(or ABA, or ABAB,…)
A = baseline period (no treatment)
B = treatment period
Multiple baseline design
Measure baseline in several situations (e.g. aggressive behavior at home, school, and day care)
Introduce treatment at different times in the different situations
Evidence for treatment effectiveness is that behavior changes only when the treatment is introduced
Problems that even true experiments may not control
Contamination
Experimenter expectancy effects/Observer bias
Novelty effects (Hawthorne effect)
Contamination
Communication between
participants
Novelty effects (Hawthorne effect):
reactivity; when participants behave differently because they know they are being studied
Developmental Research Designs
Used to study changes in behavior associated with age
Cannot use random assignment
Usually amounts to a correlational study
Cross-Sectional Method
Randomly select participants from different age groups
Different participants make up each age group
Advantage: relatively fast
Disadvantage: cohort effects (generation effects)
Cohort
A group of people born at the same time
Cohort Effects
effects due to unique experiences of a
particular generation rather than age itself
Longitudinal Method
Single group of participants is followed over time and tested repeatedly
Can take a long time
Cohort effects are not an issue when drawing conclusions about the specific generation
May be cross-generational effects – conclusions may not apply to other generations
Other problems of longitudinal designs
Mortality (attrition)
Multiple-observation effect
Sequential Method
combination of cross-sectional and longitudinal
observe different age groups
follow those age groups over time
If we have three or more levels of our IV,
we perform an ANOVA to compare the means
Complex Designs
two or more IVs are manipulated simultaneously in a single experiment
Interaction:
When the effects of one variable depend on the level of another variable
When the effects of one variable are different for different levels of another variable
Factorial Design
an experimental setup that studies the effects of two or more independent variables simultaneously, including their interactions.
The simplest factorial design is
a 2x2 design (two IVs, with two levels for each IV)
- something with less than two levels is not a variable
