Independent variable is that element of experimental research, which is manipulated or changed by the research in order to cause changes in other elements being studied. Therefore, the independent variable is one of the core or major components of experimental research. It is the variable that is altered or manipulated by the researcher to bring forth another variable, the dependent variable, in the course of a research study. The independent variable is also known by other terms such as the manipulated or grouping variable because of its role in the study. Additionally, this variable may have more than two levels or categories in relation to the different categories of the variable that affect the experiment.
There are at least two levels of independent t variables, although some studies may have up to five levels. The levels of independent variables refer to the various amounts or types of the independent variable used in an experiment. For instance, in an experiment seeking to find out the impact of different dosages of a specific drug on the behavior of patients, the independent variable is the drugs.in this research, however, while the independent variable is the drug, different categories of the drug such as the different dosages also affect the findings of the study.
Therefore, one experimental study can have more than two levels of the independent variable, most especially if it compares between the control and experimental treatment. For example, in research seeking to compare the influences of diet on the health of an individual, it is very likely that this study will have more than two levels. This is because of the different types of diets and how each of them affects individual behavior. Consequently, the levels of independent variables in a study depend on the number of experimental conditions that exist for the particular research experiment. Therefore, some studies are bound to have two or more levels of independent variables.
There are several reasons why researchers use various levels of one independent variable. First, it is to address the different conditions that may affect the quality of the study. For instance, in the experiment of food diet stated above, it can be inconclusive if the study only bases its experiment and findings on one type or level of diet. This is because it would not provide an answer to all the issues relating to diet and health. Therefore, different levels of independent variables also clarify the scope of the study as well as make the study clearer in terms of the issues investigated.