The two types of variables in research are the dependent and independent variable. Use this lesson to learn more about the dependent variable so that you can develop good research questions and conduct appropriate social research.
Dependent Variables Defined
There are two different kinds of variables: dependent variables and independent variables. In this lesson we will explore both variables as one cannot adequately be understood without explanation of the other.The ‘dependent’ variable cannot change or grow unless something else is happening or influencing it. What might be influencing the dependent variable is the ‘independent variable.’ The independent variable can stand alone all by itself and does not require anything else to happen in order for change or growth to occur.
Scientific research is conducted quite often in sciences fields, such as sociology, psychology, medicine, nursing, etc. The scientific method is used to conduct the research and requires that you develop a research inquiry and then devise a plan to test that inquiry by using variables. In order to more fully understand the scientific research method, you must first understand that the researcher always aims to learn more about something, discover a new concept or theory, uncover a new process or helpful procedure, or identify trends and themes.The variables play an important part in determining the answer to the questions being asked in any research that employs the scientific method. The variables can be many different things based on the research questions that are created by the researcher or what the researcher is aiming to explore.Let’s say that a researcher has become interested in exploring how community members’ income is affected by their age. Researchers may ask a question such as: ‘Does age affect the income levels of the members living in this community?’ They may also be interested to explore the range of careers the community members have acquired and if those careers primarily require a higher education degree, so they may ask: ‘Does the educational levels of the community members have any bearing on their career levels?’These are simple examples of research questions that involve both dependent and independent variables.
Let’s take a closer look at the variables in both questions.The first question: Does age affect the income levels of the members living in this community?Age is a variable that will not be dependent on anything else. We are asking if someone’s income levels are dependent on their age. Therefore, we have determined that the variable of ‘age’ is the independent variable and can stand alone on its own. People will continue to age without anything or any other variable influencing their growth in years. On the other hand, income levels can change and are dependent on many things including levels of education, years of experience, and perhaps one’s age.
We are trying to measure income levels. Age could affect those levels. Therefore, we can determine that perhaps ‘income levels’ are dependent on one’s age. In conclusion, the variable of ‘age’ is the independent variable (it can change and grow without anything else happening) and the variable of ‘income levels’ (which must change or grow because of something that has or will happen) is the dependent variable.The second question: Does the educational levels of the community members have any bearing on their career levels?Being able to achieve a level of education is an accomplishment that is independent and can stand on its own. It does not require anything else other than attending and succeeding in college.
However, there is a chance that some career levels beyond entry-level, such as supervisory, managerial, professional, technical, etc., may not be attainable without first having acquired a certain level of education.Therefore, we can determine that perhaps one’s ‘career level’ is dependent on one’s ‘level of education.
‘ In conclusion, the variable of level of education is the independent variable (it can change and grow without anything else happening) and the variable of career level (which must change or grow because of something that has or will happen) is the dependent variable.
In summary, the dependent variable must change or grow because of something that has happened or will happen. The dependent variable can be something that is observed based on changes or an intervention that is taking place (the independent variable). While the independent variable can stand alone, the dependent variable exists in connection or is tested in connection with the independent variable.