“To Measure Is To Know”

Posted November 23rd, 2010 by

Always check primary sources….

This was the title of a brief message sent to me from Paul Wicks, our head of research here at PatientsLikeMe.  He was referring to a quote I have used as my email signature for the last few years; he had discovered I had wrongly attributed it to Archimedes.

“To measure is to know” is the quote in question.  I originally sourced it when searching on Google for quotes on measurement, which is one of my passions.  I believe I found it on this website where it is listed among a number of business quips.measureknowimage

The irony is not lost on me that the Internet fooled one of the founders of a company that sells scientific data collected on the Internet into using a false reference.

I suppose it is possible that Archimedes, as one of the founders of modern science, believed in the value of measurement and might have said some Greek variation of the phrase.  Unfortunately for me though, a reasonably extensive search does not indicate there is any evidence he actually uttered those words or anything like them.  “To measure is to know” perhaps most appropriately belongs to Lord Kelvin and a search on Google yields 12,000 hits for this linkage.  When I look deeper though and search for primary sources, I am not confident that that I can find a citation to a time he used wrote or said those exact words (note to the crowd: send me a reference if you have one).  The phrase is clearly a more concise version of this quote which appeared in Electrical Units of Measurement, Vol 1, 1883-05-03.

“When you can measure what you are speaking about,
and express it in numbers, you know something about it”
- Lord Kelvin

One of my first rules of research is if you screw up, then admit it loudly and learn from it.  So I admit my error loudly and I sincerely apologize to those that have referenced my use of the quote.

I think there are several lessons here for all of us as we embark on this journey of using the Internet to do medical research.

  1. Many hits do not make something true.
  2. Interpretation errors can come in many forms.

It turns out you can fool most of the people sometimes and this is true in literary references and in the kind of data we collect at PatientsLikeMe.  This calls on us to be extremely rigorous in checking the primary sources we use. By using all the tools at our disposal, we must verify that we are not being fooled by errors of bias, noise or wishful thinking.  It also demands that we are precise in our assertions of the meaning of our data, so that it describes what we know and not what we might believe.

I learned a long time ago that reading a news story or even an abstract about a research paper is a very different experience than reading the actual paper itself.  While one often finds something interesting, funny, or quotable in the news or the abstract, the paper rarely contains the assertion when it is carefully examined and the limitations of the data and its sources are known.

Sadly my false attribution to Archimedes on Twitter, email and in PowerPoint slides has become a new source of validation for the quote.  If you do a Google search of  “To measure is to know, Archimedes,” you’ll now find links to my sources and those of several of my friends who mistakenly trusted me to be reliable.  It will be hard to correct these and it is likely someday someone else will use this misquote and inappropriately cite me as a source.  To those people, I again apologize and hope this correction rises to the top of the Google search.

It can be dangerously self-reinforcing to make assertions in the age of the Internet with its replication and failure to generally reference correctly.  This means that those of us who value truth should make those assertions very, very carefully.

So I am updating my signature for a while a new quote and a link to this essay.

“Always check primary sources”
- Paul Wicks, Ph.D.

P.S. – I am fairly comfortable contributing that quote to Paul.  Though it is to some degree a common sense concept I think Paul’s use and context are original enough that an attribution is justified.  A Google search reveals that that exact wording is only found 443 times (as of Nov 17 2010).  The top 30 or so were mostly in long form text and not really in quote style.

PatientsLikeMe member jamie


One Comment

  1. [...] these kinds of things right or not. But in his story about researching this same Lord Kelvin quote, James Heywood of patientslikeme makes some good points about the value of checking primary [...]

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