「One day he was explaining Baka-Poka, fool-proofing devices, created and implemented by workers on the factory floor. A young woman started to cry. "Why are you crying?" He asked. "Because I am not a fool," she answered. "I am truly sorry." And at that exact moment he changed the name from Bata-yoke to Poka-yoke, mistake-proofing devices. 」
有一天，他解釋防呆裝置 (Baka-poka, fool-proofing devics)，是為工廠內的工人而創造並使用的。一個年輕的女人開始哭，他問「為什麼哭？」，「因為我不是傻子」，「我真的很抱歉。」新鄉立即把名字改成防錯裝置 (Poka-yoke device)。（資料來源：Strategos, Inc. 的訪問資料 《Pioneers of Lean Manufacturing - Taiichi Ohno and Shigeo Shingo》）
This poka-yoke concept is actually based on the same idea as "foolproofing", an approach devised mainly for preserving the safety of operations. In the early days I used the term "foolproofing" (in Japanese, bakayoke).
…. It was clear to me that "foolproofing" was a poorly chosen term. But what name would ibe suitable? After some thought, I gave the name poka-yoke (mistake-proofing) to these devices because they serve to prevent (or 'proof;' in Japanese, yoke) the sort of inadvertent mistakes (poka in Japanese) that anyone can make". （資料來源：網路部落格，The Origin of Fool-Proofing System or Poka-Yoke）
In fact, the original term (of poka-yoke) was Baka-Yoke or "fool-proof". Due to the inappropriateness of the term, mistake-proofing became the preferred term.