Study design selection
Begin with a precise research question, define the target population and outcome, then choose a study design that answers the question ethically and with feasible data.
Open interactive lesson & self-check ↗Study designs: where do you start?
Original conceptual SVG · scalableA simplified decision map; study ethics, temporal sequence, feasibility and bias safeguards before selecting a design.
Define the question
Use a structured question such as population, exposure or intervention, comparator, outcome and time frame when appropriate. Specify a single primary outcome before collecting data.
Match design to goal
Descriptive studies characterize populations; cohorts establish temporal ordering; case–control designs are efficient for some rare outcomes; randomized trials compare assigned interventions.
Predefine bias safeguards
Specify sampling, eligibility, missing-data strategy, confounders, ethical approval, preregistration where applicable and a reproducible analysis plan.
Reference and next reading
Explore the original curriculum and publisher-hosted resources for full-depth reading; this note is an original schematic introduction, not an exhaustive chapter.