What type of research design focuses on the collection of numerical data?

Quantitative research is characterized by its focus on the collection and analysis of numerical data. This type of research is designed to quantify variables and establish patterns, relationships, or statistical significance through the use of various quantitative methods such as surveys, experiments, or observational studies. It allows researchers to draw conclusions that can often be generalized to larger populations due to its reliance on structured measurement and analysis.

In contrast, qualitative research emphasizes understanding concepts, experiences, and meanings, often using non-numerical data such as interviews and open-ended questions. Exploratory research aims to investigate a problem or phenomenon when there are limited existing theories or prior knowledge, typically using qualitative methods. Case study analysis, while it may involve numerical data, primarily provides a deep, detailed examination of a single case or small number of cases, often using qualitative methods to explore complex issues.

Thus, the distinguishing factor of quantitative research is its reliance on numerical data to derive conclusions, making it the correct choice in this context.