chapter 10
degree to which the research strategy limits confounding and controls threats to internal validity
distinction between nonexperimental and quasi-experimental research design
nonexperimental
research design makes little or no attempt to minimize threats
quasi-experimental
makes some attempt to minimize threats to internal validity and approaches the rigor of a true experiment
nonexperimental and quasi-experimental research stratgies
involve comparison of scores from different groups or different conditions. these two strategies use a nonmanipulated variable to define the groups or conditions being compared.
nonequivalent group design
research study in which the different groups of participants are formed under circumstances that do not permit the researcher to control the assignment of individuals to groups.
differential research design
simply compares preexisting groups. type of nonexperimental research design
- Differential Research Design
- Posttest-Only Nonequivlent Control Group Design
Nonexperimental designs with Nonequivalent groups
nonequivalent control group design
uses preexisting groups, one of which serves in the treatment condition and the other in the control condition
Posttest-Only Nonequivalent Control Group Design
one group of participants is given a treatment and then is measured after the treatment. the scores of the treated group are then compared with the scores from the nonequivalent group that hasn't received treatment
Pretest-Posttest Nonequivalent Control Group Design
Quasi-Experimental Design with Nonequivalent Groups
Pretest-Posttest Nonequivalent Control Group Design
one group is measured twice, once before and once after the treatment. the other group is measured at the same two times but does not receive any treatment
pre-post design
research study in which a series of observations is made over time for ONE group of participants.
H.R.M.I.T.
threats to internal validity for Pre-Post design