Quantitative research, also called "empirical research," is research based on traditional scientific methods which generate numerical data and seek to establish causal relationships between two or more variables, using statistical methods to test the strength and significance of the relationships. Observations in quantitative research are measured in numbers.
Quantitative research starts with a testable hypothesis. One of the goals of quantitative research design is others can repeat the findings of the study. Some examples of quantitative research methods include close-ended interviews, surveys, clinical trials, and lab experiments.
Adapted from Finding Quantitative or Qualitative Nursing Research Articles (Simmons University)
Four main types of quantitative research design:
Descriptive Design - Seeks to describe the current status of a variable or phenomenon. The researcher develops a hypothesis after the data is collected. Data collection is mostly observational.
Correlational Design - Explores the relationship between variables using statistical analyses. The researcher does not look for cause and effect. Data collection is mostly observational.
Quasi-Experimental Design - Seeks to establish a cause-effect relationship between two or more variables. The researcher does not assign groups or manipulate the independent variable. Control groups are identified and exposed to the variable. Results are compared with results from groups not exposed to the variable.
Experimental Design - Uses the scientific method to establish cause-effect relationship among a group of variables in a research study. Researchers make an effort to control all variables except the one being manipulated (the independent variable). The effects of the independent variable on the dependent variable are collected and analyzed for a relationship.
Adapted from Quantitative Approaches - Center for Innovation in Research and Teaching
An Introduction to Quantitative Research (37 mins)
From Academic Videos Online, this video presented by Jaime Dyce covers seven areas: an introduction to quantitative research, quantitative data collection, experimental design, quantitative analysis, quantitative and qualitative methodologies, writing research reports, and ethics.
Quantitative Research Designs: Descriptive non-experimental, Quasi-experimental or Experimental? (YouTube)
Students often have difficulty classifying quantitative research designs. In quantitative research, designs can be classified into one of three categories: descriptive non-experimental, quasi-experimental or experimental. To identify which of these designs your study is using follow the steps in this video.