Quality of hire is the metric that tries to answer the only question that ultimately matters: did the people you hired turn out to be good. It links a hiring decision back to what happened afterward, usually some blend of performance, how quickly the person ramped up, and whether they stayed. It is the most important thing to measure in hiring, and also the hardest, because the outcome only becomes clear months after the decision.
Because it is hard to measure, many teams fall back on things that are easy to count instead, like time to hire or cost per hire. Those matter, but a fast, cheap hire that does not work out is not a good one. Quality of hire is the check that keeps efficiency honest.
The practical way to improve it is to make hiring decisions more consistent and more evidence-based, which is exactly what structured interviews and scorecards do. Decisions grounded in defined criteria and recorded evidence are far easier to connect to later outcomes than gut-feel calls, so over time you can actually learn what predicts a good hire and do more of it.