More on Less!

Jerry McCourt in Lakebay, Washington, writes:

The use of “x times less” is one of my pet peeves, as well. (February 21, 2016) I caught Jared Diamond, author of Guns, Germs, and Steel, making the same mistake in an article on the Perry expedition to the North Pole published in Natural History Magazine. He wrote that Perry invented sledges that were “ten times lighter” than those used on previous expeditions. I wrote to the editors about the mistake and was surprised that they published my letter in a later issue

The mistake occurs frequently even in publications that should be mathematically knowledgeable. For example, Astronomy Magazine often describes objects as “twice as small” or “twice as close.” But the mistake shows up most often, by far, in the popular press, such as a headline stating that the value of the Russian ruble dropped 300% against the American dollar.

I counseled the students in my critical thinking classes never to trust percentages or “times” figures unless the article also includes the numbers on which the comparison is based.

Thanks for your work trying to keep people thinking clearly.

Marilyn responds:

Thank you, Jerry.