Publication Bias
The tendency for studies with positive or statistically significant results to be published more often than studies with null or negative results, distorting the evidence base.
In Depth
Publication bias is a significant concern in cannabis research, where commercial interests and advocacy may influence which studies are published and how results are framed. Funnel plot asymmetry in meta-analyses can detect publication bias. Trial registration (ClinicalTrials.gov) and pre-registration of analysis plans (e.g., on OSF) help mitigate publication bias by creating a public record of all initiated studies, including those with null results.
Related Terms
More in Research Methods
Randomized Controlled Trial (RCT)
The gold standard study design in clinical research. Participants are randomly assigned to treatment or control groups to minimize bias and establish causation.
Systematic Review
A structured synthesis of all available evidence on a specific research question, using predefined criteria to identify, evaluate, and summarize studies.
Meta-Analysis
A statistical technique that combines quantitative data from multiple studies to produce a pooled estimate of effect size with greater statistical power than any individual study.
Placebo-Controlled
A study design in which the control group receives an inert substance (placebo) identical in appearance to the active treatment, to account for the placebo effect.
Observational Study
A study in which researchers observe participants without intervening. Includes cohort studies, case-control studies, and cross-sectional surveys.