Which research study design is an example of quantitative research?

Quantitative research is characterized by its structured approach to collecting and analyzing numerical data, which allows for statistical analysis and the establishment of patterns or relationships. Randomized controlled trials (RCTs) exemplify this approach because they involve the systematic allocation of participants to different groups (such as treatment and control) to assess the effectiveness of an intervention while minimizing bias and confounding variables. This design typically includes specific outcome measures that can be quantified, enabling researchers to draw conclusions based on numerical data and statistical significance.

In contrast, case studies and focus groups usually emphasize qualitative research methods, focusing on individual experiences or group discussions without the structured data collection that defines quantitative analysis. Similarly, surveys that collect open-ended responses do not generate quantifiable data, making them unsuitable examples of quantitative research. Thus, the RCT stands out as the correct choice for illustrating a quantitative research design.