Observational uncertainty refers to the inherent limitations in measuring a quantity or observing an event due to factors such as instrumentation, data collection methods, and environmental conditions. It is the degree of imprecision that arises from making measurements using available tools and techniques, rather than any intrinsic properties of the phenomenon being observed. In other words, it reflects the limitations in our ability to accurately observe or measure a particular phenomenon, rather than any inherent uncertainty in the phenomenon itself.