What term describes how close a measurement is to the bullseye?

The correct term that describes how close a measurement is to the bullseye is accuracy. Accuracy refers to the degree to which a measured value reflects the true value of the variable being measured. In the context of targeting, if a measurement is close to the bullseye, it indicates that the measurement is very close to the intended target or actual value, demonstrating high accuracy.

On the other hand, precision is about the consistency of measurements, indicating how reproducible they are when repeated under the same conditions. Reliability refers to the dependability of a measurement or assessment over time and across different instances, while validation involves confirming that a measurement or assessment actually measures what it is intended to measure. Each of these terms plays a different role in understanding measurements and data, but for the concept of closeness to a target, accuracy is the precise term.