What is a research design? Explain its types with suitable examples.

1. 1 · Open with a definition. Research design is the blueprint of a study: the plan for collecting, measuring and analysing data.
2. 2 · Features of a good design. Minimises bias, maximises reliability, suits the objective, and fits the time and money available.
3. 3 · Draw a chart of the types. [Chart: research design → exploratory | descriptive and diagnostic | hypothesis-testing (experimental)]
4. 4 · Explain each type with an example.
   • Exploratory: flexible, for new insight.
   • Descriptive: describes a group accurately.
   • Diagnostic: frequency and associations.
   • Experimental: tests cause and effect with a control group.
5. 5 · Add the experimental designs.
   • Before-and-after without control.
   • After-only with control.
   • Before-and-after with control.
   • Formal: randomised, randomised block, Latin square, factorial.
6. 6 · Mention other classifications. Ranjit Kumar: cross-sectional, before-and-after, longitudinal; retrospective, prospective; experimental, non-experimental, quasi-experimental.
7. 7 · Nutrition example. A survey of anaemia in college girls is descriptive; a fortified-rice trial in schools is experimental.
8. 8 · Close in one line. The right design makes the answer to the research question valid and reliable.

Scoring tip: Draw the chart of types first, then give one nutrition example under each type.