Which research design type often involves structured interviews and questionnaires?

The correct answer highlights that both quasi-experimental and true experimental designs can involve structured interviews and questionnaires. These research designs are commonly deployed in social work and other social sciences to gather data systematically.

In true experimental design, researchers apply random assignment to participants into control and experimental groups, allowing for a rigorous assessment of causal relationships. Structured interviews and questionnaires can be used here to collect quantitative data from participants before and after they experience an intervention, ensuring that the outcomes can be compared effectively.

Quasi-experimental designs, while lacking random assignment, still aim to evaluate interventions or programs but do so in naturalistic settings where randomization may not be ethical or feasible. These designs also benefit from structured interviews and questionnaires to evaluate the impact of an intervention, helping to collect data on participants' experiences and outcomes.

By utilizing structured interviews and questionnaires, researchers can obtain reliable and valid information that is vital for analyzing the effects of various social interventions, making it a critical component across both types of designs.