Chapter 4: Measurement and Units of Analysis
4.5 Independent and Dependent Variables
When one variable causes another variable, we have what researchers call independent and dependent variables. In the example where gender was found to be causally linked to cell phone addiction, gender would be the independent variable (IV) and cell phone addiction would be the dependent variable (DV). An independent variable is one that causes another. A dependent variable is one that is caused by the other. Dependent variables depend on independent variables. If you are struggling to figure out which is the dependent and which is the independent variable, there is a little trick, as follows:
Ask yourself the following question: Is X dependent upon Y. Now substitute words for X and Y. For example, is the level of success in an online class dependent upon time spent online? Success in an online class is the dependent variable, because it is dependent upon something. In this case, we are asking if the level of success in an online class is dependent upon the time spent online. Time spent online is the independent variable.
Table 4.2 provides you with an opportunity to practice identifying the dependent and the independent variable.
Practice Exercise: Practice choosing the dependent and independent variables. Identify the dependent and independent variables from the questions below.
Dependent Variable | Independent Variable | |
1. Is success in an online class dependent upon gender? | ||
2. Is the prevalence of post-traumatic stress disorder in Canada dependent upon the level of funding for early intervention? | ||
3. Is the reporting of incidents of high school bullying dependent upon anti-bullying programs in high school? | ||
4. Is the survival rate of female heart attack victims correlated to hospital emergency room procedures? |
Answers:
- Dependent variable = success in online class; Independent variable = gender.
- Dependent variable = prevalence of PTSD in BC; Independent variable = level of funding for early intervention.
- Dependent variable = reporting of high school bullying; Independent variable = anti-bullying programs in high schools.
- Dependent variable = survival rate of female heart attack victims; Independent variable = hospital emergency room procedures.