Research Methods — Critical for CARS & Sciences

Study types:

Randomized controlled trial (RCT) — gold standard; random assignment to treatment/control; can establish causation

Cohort study — follow groups over time; good for incidence; can show correlation

Case-control — compare those with disease to those without; good for rare diseases; retrospective

Cross-sectional — snapshot in time; shows prevalence

Meta-analysis — combines data from multiple studies; increases power

Statistics:

Mean — average; sensitive to outliers

Median — middle value; not affected by outliers

Mode — most frequent value

Standard deviation (SD) — spread around mean; normal distribution: 68% within ±1 SD, 95% within ±2 SD

Validity vs. Reliability:

Validity — measures what it claims to measure

Reliability — consistent, reproducible results

p-value: Probability results are due to chance. p < 0.05 = statistically significant. Confidence interval: range within which true value likely falls.

Reference:

Wikipedia: Research Methods

https://en.wikipedia.org/wiki/Research_methods