Inspection
The Scrum pillar of frequently and diligently examining artifacts and progress toward agreed goals to detect undesirable variances.
What it means
Inspection happens at the Scrum events: the Daily Scrum inspects progress toward the Sprint Goal, the Sprint Review inspects the Increment, and the Sprint Retrospective inspects how the team worked.
Inspection should not be so frequent that it gets in the way of the work, but frequent enough that meaningful changes can be detected quickly, a balance every team calibrates through experience.
Common mistakes
Skilled inspectors are diligent: they look past status reports to the actual state of the work, which is why the Definition of Done matters as an objective standard for judging an Increment.
Example
During the Sprint Review, stakeholders inspect the live Increment rather than a slide deck describing it.