experimental research strategy Flashcards
4 basic elements
manipulation, measurement, comparison and control
between-subject design
random assignment into group , 2 or more treatment groups , each group gets a different treatment , independent groups
within-subject design
all subjects participate both groups (but can randomize order), only 1 treatment group, subjects get both treatment, repeated measures design.
between-group variability
bigger separation by using more extreme manipulation
Within-group variability
large individual differences can lead to large variance within treatments and decrease study success, unavoidable
mitigating variance
standardize procedures and treatment setting , sample size , group equivalency
pretest-posttest design
before manipulating independent variable, check if the 2 groups are equivalent : compare treatment and control group
Within-subjects design – Advantages
fewer participants needed, eliminate variability due to individual differences,
Within-subjects design – disadvantages
participant attrition, not applicable to all studies, time related effects
Counterbalalncing
balancing the order effect equally among the 2 groups
history
environmental or outside event other than the treatment changes over time and affect the results
maturation
any physiological or pscychological change of individuals when testing occurs over a long period of time
instrumentation
change in measuring the instrument lead to significant differences at testing independent of the treatment
order
ordinal position of the manipulation can produce practice and/or fatigue “carry-over effects”
sequence
interaction between each condition in the experiment can reduce sensitivity of response
