Flashcards in Ch10Research Deck (18):
What does the term 'group' refer to?
treatment of the data, not how the treatment is administered
What are some of the assumptions of group designs?
variability is intrinsic to human subjects; the statistical differences between group averages will represent true differences between or among groups; it is possible to create truly random samples; results of a valid experiment can be generalized
What are 'randomized controlled trials' (RCTs)?
the IV (tx) is subject to the controlled manipulation of the investigator and the DV (measures or outcomes) are collected under controlled conditions
What does 'randomized' refer to of RCTs?
the random allocation of participants to treatment and control groups
What are some of the cautions about RCTs?
it is nearly impossible to obtain a true random sample, it is difficult to identify all members of a clinical population, researchers can only use participant who volunteer
What are some design examples of the single-factor experimental design?
pretest-posttest control-group design, posttest-only control-group design, single-group pretest-posttest design, nonequivalent control-group design time series design, repeated measures or repeated treatment designs
Why are multiple-factor experimental designs typically used?
because the researcher is interested in not only the individual effects of the multiple factors on the DV, but also in the effects of the interaction between the multiple factors on the DV
What are some design examples of the multiple-factor experimental design?
factorial design, nested design, completely randomized design, randomized-block design, between-groups design, within-groups design, mixed designs
Pretest-Posttest Control Group Design
R O X O
R O O
R O X1 O
R O X2 O
Posttest-Only Control Group Design
R X O
Single Group Pretest-posttest Design
O X O
Time Series Design
O O O O X O O O O
Factors are crossed meaning that each level of one factor is combined with each level of each other factor
When all the factors do not cross one another
One of the factors of interest is not variable; Participants are placed into blocks based on an attribute (ex: gender) and then randomly assigned to treatments
At least one between-subjects factor and one within-subjects factor
Between Groups Design
different groups get different levels of researcher manipulable treatments