Published in the United States and some other countries under the title "The Perfectionists", Simon Winchester's book "EXACTLY" is exactly the same - and what a totally fascinating read it is!
Since I am not mechanically-minded, I may not have read this book if it had been written by someone else, but I've read so many other books by Simon Winchester that I couldn't resist. I prefer non-fiction books, and Simon Winchester wrote some thirty non-fiction bestesellers: "Pacific", "Atlantic", "Krakatoa", "The Man Who Loved China", "The Map That Changed the World", "A Crack in the Edge of the World", "Land", "Knowing What We Know", "Outposts", "The River at the Centre of the World", "The Alice Behind Wonderland", "The Professor and the Madman", "The Breath of the Gods", "The Rise and Fall of Travel", and there are more.
Although I am still not mechanically-minded, I was not disappointed by the book, as I took away an explanation of the words "precision" and "accuracy". As Simon Winchester writes on page 12: "In the following account, the words precision and accuracy will be employed almost but not quite interchangeably, as by common consent they mean just about the same thing, but not exactly the same thing — not precisely."
And he continues: "If you describe something with great accuracy, you describe it as closely as you possibly can to what it is, to its true value. If you describe something with great precision, you do so in the greatest possible detail, even though that detail may not necessarily be the true value of the thing being described.
You can describe the constant ratio between the diameter and the circumference of a circle, pi, with a very great degree of precision, as, say, 3.14159265358979323846. Or pi can happily be expressed with accuracy to just seven decimal places as 3.1415927."
So, in engineering at least, there is a clear difference between the two. Precision describes how variable an outcome is, or how close repeated measurements or actions are to each other. Accuracy is how close you are to the true or intended value. If you’re hitting near your intended target then you’re accurate.
After you have read Simon Winchester's book, you will be able to explain to your friends with great precision the meaning of the word "accuracy".
