The correct answer is: B. Replication
An experimental study is a type of research that involves manipulating one or more variables to observe the effect on another variable. The goal of an experimental study is to determine whether there is a cause-and-effect relationship between the variables.
In order to determine whether there is a cause-and-effect relationship, it is important to replicate the study. Replication means repeating the study with different participants, different settings, and different researchers. This helps to ensure that the results of the study are not due to chance or to factors other than the manipulated variable.
The other options are incorrect because they are not necessary for an experimental study. A single variable can be manipulated in an experimental study, but it is not necessary. Occupation and interest in the subject are also not necessary for an experimental study.
Here is a more detailed explanation of each option:
- A. Single variable. A single variable is a variable that is changed or manipulated in an experimental study. The goal of an experimental study is to determine whether there is a cause-and-effect relationship between the manipulated variable and another variable. In order to determine whether there is a cause-and-effect relationship, it is important to control all other variables. This means that the only variable that should change between the experimental group and the control group is the manipulated variable.
- B. Replication. Replication means repeating the study with different participants, different settings, and different researchers. This helps to ensure that the results of the study are not due to chance or to factors other than the manipulated variable.
- C. Occupation. Occupation is not necessary for an experimental study. Participants can be from any occupation.
- D. Interest in the subject. Interest in the subject is not necessary for an experimental study. Participants can be interested in the subject or not interested in the subject.