Underreporting refers to the phenomenon where certain crimes or incidents are not reported to authorities, leading to a significant gap in crime data and statistics. This can occur for various reasons, including victim fear, lack of trust in law enforcement, or a belief that the crime is not serious enough to warrant reporting. Underreporting has a direct impact on the accuracy of official crime statistics, victimization surveys, and self-report studies, as it contributes to the 'dark figure of crime,' which represents unrecorded offenses that distort our understanding of crime prevalence.