Quasi- Experiments
What is the defining characteristic of quasi experimental designs
Participants cannot be randomly assigned to levels of an independent variable
How does one inquire about the internal validity of quasi experimental designs
Ask about alternative explanations
T or F; real world implications are a large motivating factor in conducting quasi-experimental studies
True
What does N refer to; what is the hallmark of a small N design
N is a statistical denotation of a sample size; small sample sizes with a lot of information gathered from the small amount of individuals who participate
What are the hallmarks of a nonequivalent control group posttest-only design
No random assignment
at least one treatment and one comparison group
tested only once after exposure to independent variable
T or F; without random assignment, selection effects are always an issue and can never be ruled out
False, researchers can take other measures to rule out selected effects such as wait-list designs (which make it a true experiment)
T or F; Correlational Studies and Quasi-experimental studies have very similar designs and structure
True, Quasi experimental studies choose participants more carefully in relation to variables of interest
Despite the small number of individuals these studies usually contain, ____ control allows for empirical efficacy
Experimental control, in small N designs experimenters have more control over tests
What is the difference between a nonequivalent control group posttest-only design and a nonequivalent control group pretest/posttest design
the former contains only a post test and the latter contain tests of the DV at multiple time period both before and after exposure to the IV of interest.
T or F; Almost all threats to internal validity outlined in chapter 11 apply to quasi experimental studies
true
Why might quasi-experimental studies be particularly helpful for external validity
Despite the control that experimenters have in small N designs, because of the fact that one individual may not represent the population very well we are presented with a _____ issue
external validity
Define interrupted time series design
Participants measured on a DV before, during, and after exposure to the IV. Again, typically selected from a population and the IV is not manipulated nor is there random assignment
History threats are
when events occur that may confound the event measured by a quasi-experimental design
Why might researchers choose quasi experimental designs for ethical purposes
Random assignment can be tricky when deciding whether an individual should be put into a certain condition however, with quasi-experimental designs, participants are already in these conditions
What are the three variations of small N designs in relation to how baselines are used, describe them briefly
stable-baseline design - study where the practitioner studies behavior or DV for a specific amount of time before treatment and then subsequent testing (establishing a baseline)
Multiple Baseline Design - staggering the introduction of a treatment across a few individuals
Reversal Designs - reversal designs will establish a baseline, then introduce treatment, then after measuring the efficacy of the treatment will remove the treatment to measure return to baseline
This quasi experimental design is characterized by two groups, measurement on the DV before, during, and after an event, and no random assignment
nonequivalent control group interrupted time-series design
History threats may be ameliorated by
adding a comparison group, similar to what the study on opioid death did by ALSO selected North Carolina to study as well as Florida
Describe the difference between Participant Variable and Quasi Independent Varaible
Participant variables are essentially a form of identity or personal factors that may define or characterize the individual, quasi independent variables are typically conditions of society or states of nature that individuals may find themselves in.