قارن الطرق

	تحليل تلوي	التحيز للنشر	Systematic Review
المجال	الكتابة الأكاديمية	إحصاء البحث	الكتابة الأكاديمية
العائلة	Process / pipeline	Process / pipeline	Process / pipeline
سنة النشأة	1976	1979	1992
صاحب الطريقة	Glass (1976, term coining); Fisher and Pearson (statistical foundations)	Robert Rosenthal	Cochrane Collaboration (1992)
النوع	Document Type	Concept	Document Type
المصدر التأسيسي	Page, M. J., et al. (2021). The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ, 372, n71.	Rosenthal, R. (1979). The file drawer problem and tolerance for null results. Psychological Bulletin, 86(3), 638–641.	Page, M. J., et al. (2021). The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ, 372, n71.
الأسماء البديلة	quantitative synthesis, meta-synthesis, pooled analysis, statistical integration	file drawer problem, selective reporting, outcome reporting bias, funnel plot asymmetry	systematic literature review, evidence synthesis, scoping review, mapping review
ذات صلة	2	4	3
الملخص	Meta-analysis is the statistical pooling of quantitative findings from multiple independent studies to produce a combined effect estimate. By aggregating data across studies, meta-analysis increases statistical power, reduces random error, and provides a precise summary of an intervention's effectiveness or an association's magnitude. Gene V. Glass coined the term in 1976, formalizing a technique that has become indispensable for evidence synthesis in medicine, psychology, education, and other evidence-based disciplines.	Publication bias occurs when the results of a study influence whether the study is published. Typically, studies with statistically significant or positive results are more likely to be published than studies with non-significant or negative results, even if both are scientifically valid. This bias distorts the published literature, making treatments appear more effective than they actually are. Rosenthal (1979) termed this the 'file drawer problem': research with null results sits in file drawers, unpublished, creating a biased sample of published evidence. Funnel plots and statistical tests (e.g., Egger test) can detect asymmetry suggesting publication bias; meta-analyses must account for this bias.	A systematic review is a structured, transparent synthesis of all available evidence addressing a specific research question. Unlike narrative reviews, systematic reviews employ comprehensive database searches, predefined selection criteria, quality assessment, and rigorous reporting (PRISMA guideline). The Cochrane Collaboration (founded 1992) established this methodology as the gold standard for evidence synthesis in healthcare and social sciences.