Publication bias occurs when the results of research studies are more likely to be published if they show positive or significant findings. This can lead to an incomplete understanding of a topic, as studies with negative or inconclusive results may remain unpublished. As a result, the published literature may overstate the effectiveness of treatments or interventions. This bias can affect various fields, including medicine and psychology, where clinical trials or psychological studies may favor positive outcomes. Researchers and policymakers rely on published studies to make informed decisions, so publication bias can distort evidence and hinder progress in understanding important issues.