Nested design :
Nested design, also known as hierarchical design or multilevel design, is a type of experimental design in which the levels of an independent variable are nested within each other. This means that the levels of the independent variable are not independent of one another, but rather they are related in some way.
One example of nested design is a study that examines the effect of different teaching methods on student achievement. In this study, the independent variable is the teaching method, and the levels are traditional, online, and blended. The traditional teaching method is when the teacher delivers the material in a traditional classroom setting, the online method is when the material is delivered online, and the blended method is when the material is delivered both online and in the classroom.
Each level of the independent variable is nested within the other, meaning that each student in the traditional group will also be in the online group and the blended group. This allows the researchers to compare the effect of each teaching method on student achievement while controlling for other variables, such as the student’s background and prior knowledge.
Another example of nested design is a study that examines the effect of different types of exercise on weight loss. In this study, the independent variable is the type of exercise, and the levels are cardiovascular, strength training, and a combination of both. The cardiovascular group only does cardiovascular exercise, the strength training group only does strength training, and the combination group does both types of exercise.
Again, each level of the independent variable is nested within the other, meaning that each participant in the cardiovascular group will also be in the strength training group and the combination group. This allows the researchers to compare the effect of each type of exercise on weight loss while controlling for other variables, such as the participant’s diet and lifestyle.
There are several advantages to using nested design in research. One advantage is that it allows researchers to control for variables that may affect the results of the study. For example, in the teaching methods study, the researchers can control for the student’s background and prior knowledge by comparing students within the same group. This helps to eliminate the possibility that these variables may be influencing the results.
Another advantage of nested design is that it allows researchers to compare multiple levels of an independent variable while still maintaining a small sample size. For example, in the exercise study, the researchers can compare the effect of three different types of exercise on weight loss with a relatively small sample size, as each participant is being compared to themselves within each group.
Finally, nested design allows researchers to compare the effects of different levels of an independent variable while controlling for other variables that may be correlated with the independent variable. For example, in the teaching methods study, the researchers can compare the effect of different teaching methods on student achievement while controlling for the student’s background and prior knowledge.
Overall, nested design is a useful tool for researchers who want to compare the effects of different levels of an independent variable while controlling for other variables that may affect the results. It allows researchers to compare multiple levels of the independent variable while still maintaining a small sample size, and it helps to eliminate the possibility that other variables may be influencing the results.