Research question
Longitudinal and cross-sectional studies differ on age, cohorts, health, knowledge, speed, and variation.
Good summaries state what was measured, who participated, when, and whether the design supports causation.
Evidence checklist
Look for transparent methods, validated measures, power, effect sizes with intervals, missing-data handling, and replication.
Statistical significance does not automatically imply a useful effect.
Reporting
Separate findings from interpretation, disclose limitations and conflicts, and link the primary paper.
Publication begins evaluation; it is not the final word.
COMMON QUESTIONS