Dr. Daniel A. Sabol
Modules
Grade 10
🔎Evaluating Sources

Research Methodology and Source Evaluation

Apply research methodology concepts — study design, sampling, confounding variables — to evaluate the quality of evidence.

12 min 3 quiz questions Grade 10
Methodology Determines Evidence Quality

The quality of a study's evidence depends primarily on its methodology — how it was designed, how data was collected, and how results were analyzed. Understanding methodology is essential for evaluating research claims.

Study Design Hierarchy

  1. Systematic reviews and meta-analyses: Synthesize multiple studies
  2. Randomized controlled trials: Random assignment controls for confounding
  3. Quasi-experimental designs: Natural experiments without random assignment
  4. Prospective cohort studies: Follow subjects forward in time
  5. Retrospective case-control studies: Look backward from outcome to exposure
  6. Cross-sectional surveys: Snapshot at one point in time
  7. Case reports and expert opinion: Weakest evidence
Confounding Variable:A variable that is associated with both the exposure and the outcome, potentially creating a spurious association between them.
Sample Size:The number of participants in a study — larger samples provide more reliable estimates and greater statistical power to detect real effects.

Statistical Reasoning

  • Statistical significance (p-value): Probability that results occurred by chance — does not indicate practical importance
  • Effect size: The magnitude of the effect — practically important even if statistically significant
  • Confidence interval: The range within which the true effect likely falls
  • Statistical power: The probability of detecting a real effect if one exists
Statistical Significance ≠ Practical Significance

A study can find a statistically significant effect that is too small to matter in practice. Always look at effect size, not just p-values. A drug that reduces blood pressure by 0.1 mmHg may be statistically significant in a large study but clinically meaningless.

Ready to test your knowledge?

3 questions · Grade 10 level

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