Single-Case and Quasi-Experimental Designs - Essay Example

In psychology, single-case and quasi-experimental designs are both applied as methods of conducting research. They only differ with regard to the assignment of participants. The difference emerges is observed in that in a quasi-experimental design, the “experimenter” does not offer any assignment of any kind to the participants. This in turn means that that firm statistical analysis is difficult to come up with. In single-case experimental design, however, the “experimenter” is wholly in charge of the experiment, and acts as the control rather than using others Jackson (2011).

In this instance in time, I have encountered several types of designs, and the obvious is that they all had, or have different [experimental] designs. One of the most outstanding was conducting research regarding the effect of expectant mothers consuming alcohol. The aim of this research which I took part in was to tell whether the myth about children whose mothers consume alcohol during pregnancy have negative effects inflicted on them. To derive the observations, class concentration and performance of 10 children who were exposed, and 10 who were not, were observed. The observations showed that the majority of the exposed children displayed more auditory, visual, and performance disabilities.

The second and slightly different experiment was data recorded in which police recorded the rate of crime (burglary) when either helicopters or cars were used to patrol a certain city over a period of one year. The results indicated that more burglaries happened when the patrol was done using cars than helicopters. In these two cases, there are both quasi and single-case experimental designs. The first experiment is quasi-experimental in that the experimenters did not set up or control the participants, but went on to assess two already-existing scenarios. In the second experiment, the police were the observers and set up two variables (helicopter and car patrols) over a defined period of one year. This fits the definition of single-case experimental designs.