Quantitative methodologies use statistics to analyze numerical data gathered by researchers to answer their research questions. Quantitative methods can be used to answer questions such as:
Quantitative methods can also be used to test hypotheses by conducting quasi-experimental studies or designing experiments.
In quantitative research, a variable is something (an intervention technique, a pharmaceutical, a temperature, etc.) that changes. There are two kinds of variables: independent variables and dependent variables. In the simplest terms, the independent variable is whatever the researchers are using to attempt to make a change in their dependent variable.
| Independent Variable(s) | Dependent Variable |
|---|---|
| A new cancer-treating drug being tested in different dosage strengths | The number of detectable cancer cells in a patient or cell sample |
| Different genres of music* | Plant growth within a specific time frame |
*This is a real, repeatable experiment you can try on your plants.
Researchers will compare two sets of numbers to try and identify a relationship (if any) between two things.
Researchers will attempt to quantify a variety of factors at play as they study a particular type of phenomenon or action. For example, researchers might use a descriptive methodology to understand the effects of climate change on the life cycle of a plant or animal.
To understand the effects of a variable, researchers will design an experiment where they can control as many factors as possible. This can involve creating control and experimental groups. The experimental group will be exposed to the variable to study its effects. The control group provides data about what happens when the variable is absent. For example, in a study about online teaching, the control group might receive traditional face-to-face instruction while the experimental group would receive their instruction virtually.
Researchers will attempt to determine what (if any) effect a variable can have. These studies may have multiple independent variables (causes) and multiple dependent variables (effects), but this can complicate researchers' efforts to find out if A can cause B or if X, Y, and Z are also playing a role.
Surveys can be considered a quantitative methodology if the researchers require their respondents to choose from pre-determined responses.