What is the design of this study?
What is the design of this study?
The following symbols will be used when diagramming the design of a study:
| X | administration of a treatment or independent variable |
| O | an observation or measurement of a dependent variable. O1 is an observation at time 1, O2 is an observation at time 2, and so forth. |
| R | random assignment to conditions |
| ---- | a dashed line separates conditions for which participants were not randomly assigned |
for example,
X O
---------
O
Each line in the diagram is a different condition in the study. There are two conditions in this design: a treatment, X, was administered to first group (the experimental group); no treatment was administed to the other group (the control group). Measurement, O, occurred posttreatment for the experimental group. The participants were not randomly assigned to the two conditions. Because randomization was not preent, this is a quasi-experimental design.
When observations occur under one another, they were taken at the same time.
adapted from -
Campbell, D. T., & Stanley, J. C. (1963). Experimental and quasi-experimental designs for research. Chicago: Rand-McNally.
-03/16/98