What does it mean that error correction has a cost?

Every correction takes time and energy — reduce the error rate rather than just correcting faster.

Example: You notice typos in every email you send, so you start proofreading each message three times before hitting send. Your error rate drops, but now a two-sentence reply takes ten minutes. You have traded one cost — embarrassment from typos — for another: time, cognitive load, and a growing backlog of unread messages. The correction eliminated the visible problem but introduced an invisible one. A colleague who uses autocomplete and a grammar checker sends the same quality of email in ninety seconds. She did not get better at correcting — she reduced the conditions that produce errors in the first place.

Try this: Pick one recurring correction you perform regularly — proofreading a document, double-checking a calculation, reviewing a process for mistakes. Time yourself doing it today. Write down three numbers: (1) how many minutes the correction took, (2) how many actual errors you found, and (3) what the cost per error caught was (time divided by errors). Then ask: what single upstream change — a template, a checklist, an automation, a constraint — could prevent half of those errors from occurring? Implement that change. Repeat the measurement in one week and compare. You are not trying to correct faster. You are trying to make correction unnecessary.