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Research Design — Previous Year Questions

📊 Topic Overview​

MetricValue
Papers Appeared7 of 28 (25.0%)
Priority🟡 MEDIUM
Section DistributionSec A: 4 | Sec B: 3
Most RepeatedObjectives and types of research design (3 times)
ProbabilityMedium

🎯 Must-Know Concepts​

  1. Definition of research design
  2. Objectives/functions of research design
  3. Types of research design (experimental, quasi-experimental, correlational, survey, qualitative)
  4. Criteria of a good research design
  5. Relationship between research design and hypothesis

🔥 Key Question: Definition, Objectives and Types of Research Design (Section A)​

Answer (~400 words):​

Definition: A research design is the overall plan or blueprint for conducting a study. It specifies the procedures for collecting, organising, and analysing data to answer the research question. Kerlinger (1986) defines it as the plan, structure, and strategy of investigation conceived to obtain answers to research questions and to control variance. It is the roadmap that guides every subsequent decision in the research process.

Objectives/Functions of Research Design:

  1. To answer research questions: The design specifies what data to collect and how, ensuring the study is capable of answering the research question.

  2. To control variance: A good design maximises explained variance (effect of IV), controls extraneous variance, and minimises error variance.

    • Maximise systematic variance: Ensure the IV conditions are sufficiently different to produce detectable effects.
    • Control extraneous variance: Use randomisation, matching, or statistical control to prevent confounding.
    • Minimise error variance: Standardise procedures, use reliable measures.

  3. To ensure internal validity: Ensures that observed effects on the DV are genuinely caused by the IV, not by confounding variables.

  4. To facilitate generalisation (external validity): Designs that use representative samples and realistic settings allow findings to be generalised.

  5. To guide data collection and analysis: Specifies what instruments will be used and what statistical analyses are appropriate.

Types of Research Design:

TypeKey FeatureExample
ExperimentalRandom assignment, IV manipulationRCT for drug efficacy
Quasi-experimentalIV manipulation, no random assignmentPre-post design in schools
CorrelationalNo manipulation, measures associationAnxiety–performance correlation
Survey/DescriptiveDescribes phenomena, no manipulationOpinion polls
QualitativeNon-numerical, interpretiveGrounded theory study
Ex-Post FactoIV occurred in past, no manipulationEffects of childhood trauma
Single-subjectIntensive study of one unitABA reversal design

Criteria of a Good Research Design:

  1. Adequacy: The design addresses the research question directly.
  2. Economy: Uses minimum resources to achieve sufficient power.
  3. Reliability: Produces consistent results if repeated.
  4. Validity: Both internal (attributing effects correctly) and external (generalising).
  5. Flexibility: Allows modification if needed without compromising integrity.

🧠 Memory Aids​

Objectives (A-C-I-G-G): Answer questions → Control variance → Internal validity → Generalise → Guide analysis

Types (EQ-C-S-Q-EP-S): Experimental → Quasi → Correlational → Survey → Qualitative → Ex-Post Facto → Single-subject

📚 Related Content​

✅ Self-Assessment​

  1. What does "controlling variance" mean in the context of research design?
  2. What is the difference between internal and external validity?
  3. Why might a researcher choose a quasi-experimental over an experimental design?
  4. What are the three types of variance that a good research design must manage?
  5. How does a research design relate to the hypothesis?

💡 Exam Tips​

  • Section A appearance is most common — full essay covering definition, objectives, types, and criteria.
  • The three-variance concept (maximise, control, minimise) is a distinctive and high-scoring point.
  • Tables for types of research design are effective and save time in the exam.