Which statement describes the role of a hypothesis in research?

The role of a hypothesis in research is to state the expected relationship between variables. This statement serves as a foundation for conducting research, as it provides a clear and testable prediction about the outcome of the study. By articulating the anticipated relationship, the hypothesis guides the research design and methodology. It helps researchers focus their efforts, determining what data to collect and how to analyze it. In essence, the hypothesis lays the groundwork for testing theories or assumptions, making it a critical component of the scientific process.

The options that discuss outlining research design or defining the sample population highlight other aspects of research planning but do not adequately capture the specific function of a hypothesis. Similarly, assessing statistical methods pertains to data analysis rather than the formulation of a hypothesis itself. Thus, the essence of a hypothesis is firmly rooted in predicting relationships between variables, making the selected answer accurate.