This study has been cited all over the world, and it's invalid.

This study has been cited all over the world, and it's invalid. We have never claimed that Britannica is error-free, but Nature attributed to us dozens of inaccuracies that simply were not inaccuracies at all. We practice strong scholarship, reasoned judgment, and continuous editorial review, and we publish a reliable, high-quality encyclopedia. By its flawed analysis and false accusations, Nature did us a great disservice.

The thing for Nature to do now is to issue a full, public retraction of the study and the article in which it was reported. They should do it immediately and correct the misleading impression they've created.

Every invalid is a prisoner

Every invalid is a physician.

It's convenient for busy automation professionals, because they can study on their own terms instead of having to travel to attend several classes.