variables.
Experimental vs. Quasi-Experimental Design
Both experimental and quasi-experimental designs are used in quantitative research. The main difference between experimental and quasi-experimental designs is that the latter does not use random assignment to control and experimental groups. With a quasi-experimental design, the control group is called the comparison group (Muijs, n.d., p. 27). To ensure validity and reliability, the researcher must ensure that population characteristics are as similar as possible between to the two groups to avoid problems with mitigating variables. For example, if a researcher wanted to test the effects of a gifted program on standardized achievement… Continue Reading...
independent and a dependent variable. A multiple regression can be used for different types of research design including correlational and true experimental designs. Moreover, the researcher can use multiple regressions when the research design includes many different variables in a complex study. In the social sciences especially, the number of confounding variables can be quite profound and often impact the validity and reliability of the research. For instance, age, gender, geography, and educational background can all impact the outcomes in a study even when the researcher only wants to study something like the effect of some medication on behavioral outcomes.
For example, I might use multiple regressions to study the impact… Continue Reading...
Some studies on the connection between heart disease and stress use experimental designs to show how specific types of stress impact physiological changes correlated with heart disease. Stress is a relatively generic term that should be qualified better in good research designs. For example, not all people react to the same situations in the same way. Some people perceive a situation as being stressful, a situation that others would not find stressful and vice-versa. It is important to classify the types of stressors and individual responses to those stressors. Locus of control has been implicated as a stressor in the workplace,… Continue Reading...