ground- water, geo- statistics, environmental- engineering, earth- science

Measurement, Error, and Uncertainty

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Norm Costa recently published on 3 Quarks Daily his thoughts on “PSYCHOLOGICAL SCIENCE: MEASUREMENT, UNCERTAINTY, AND DETERMINISM” (part 1 and part 2).

A lot of his thoughts are mostly relevant to psychology, but I will try and extract some thoughts that are relevant to an environmental modeller. Mostly the thoughts that are relevant are related to measurement, error and uncertainty.

I do have a hard time on commenting on Costa’s thoughts, but I think they are well worth to be read and thought about!


  • a measurement is a comparison to a standard;
  • standards do not last;
  • I recently came across a funny unit: 1 knot, which is the velocity of a vessel which travels one minute of geographic latitude in one hour
Alternative Text

Measurement of Precipitation

Photo by wfyurasko


Costa does treat “error” not so much in a sense as in “measurement error”, but in terms of “what is research” and how do scientists deal with research and progress in research.

I like comparing scientific psychology with psychics because it dispels many false notions of science and makes room for psychology in the pantheon of science. For example:

  • It dispels the notion that ‘real’ science is exact, objective, and dispassionate; Also, it blunts the objections of those who dismiss psychological science as inexact, subjective, and self-absorbed.
  • It dispels the notion that there is such a thing as an exact science; Rather there are sciences that deal with relatively smaller errors of measurement (physics,) and others that deal with relatively larger errors of measurement (econometrics.) Psychology lies between the two in terms of the size of errors of measurement.
  • Few scientists are objective and dispassionate in the absolute; Rather, science, by the way science is conducted, is self-correcting, in the long run, and keeps scientists on the straight and narrow.
  • Scientists are not free of biases, preconceptions, misconceptions, and personal agendas; Rather, these can fuel the energy, motivation, and creativity of scientists.
  • No scientific knowledge is absolute, unchanging, or final; Rather, all scientific knowledge is proximate and provisional, and only represents the best we can produce to this point in time. We can count on better data in the future superseding present-day knowledge.


In his discussion on uncertainty, Costa talks quite a bit about Heisenberg’s uncertainty principle and how it relates to psychology. Here are two relevant passages:

For Heisenberg and all of quantum physics, UNCERTAINTY IS A PROPERTY OF NATURE. For scientific psychology, uncertainty is a function of the limitation of our measurement tools, not a property of nature.

Einstein’s view of the world was a deterministic one: Knowledge of an outcome is certain, provided all factors and antecedents are known. For quantum physics, outcomes are uncertain (probabilistic) because uncertainty is a property of nature, not a function of inadequate measuring. Einstein’s objection to this is captured in his famous statement, “God does not play dice.” In fact, God does play dice. God spends the whole damn day playing dice. Paradoxically, Einstein, the man who gave birth to quantum physics, could not accept Heisenberg’s ‘Uncertainty Principle’ and was forever bypassed by science and left to doter in the backwater of physics.

Written by Claus

February 28th, 2010 at 4:17 pm

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