http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#discussion http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3631
When we do teacher/educator workshops for our Day in the Life of the Hudson River program we discuss how to improve the reproducibility of this semi quantitative measure. We discuss how making replications of the measurements averages out some of the variance caused by the subjectivity of the measurements. ]]> Margie Turrin 1257559560 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3631 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3632 http://www.ldeo.columbia.edu/edu/k12/snapshotday/
School groups from the full length of the Hudson watershed go to their local patch of river on one specific day each fall and make a standard set of observations and measurements. The data are shared over the Internet and accumulate over the years, so kids can use the data to look at spatial and temporal variability in their own local environment.

The secchi disk or sight tube for measuring turbitidy is an interesting example of turning nature into numbers, because the sensor is actually a human sense, sight, but it's been augmented by a device. We have a lot of devices for augmenting human sight, but the ones that come most easily to mind are for seeing things that are otherwise too small to see (microscope) or too far away to see, in other words devices for increasing visual acuity. In the case of the Secchi disk, the device augments the reproducibility of human vision, so that the recorded value is something close to the same no matter who does the measurement. ]]> Kim Kastens 1257725700 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3632 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3642 She elaborates (p. 175-176): Our culture, obsessed with numbers, has given us the idea that what we can measure is more important than what we can't measure...It means that we make quantity more important than quality... if we motivate ourselves, and reward ourselves on our ability to produce quantity, then quantity will be the result... Pretending that something doesn't exist if it's hard to quantify leads to faulty models... Human beings have been endowed not only with the ability to count, but also with the ability to assess quality. Be a quality detector. Be a walking, noisy Geiger counter that registers the presence or absence of quality... Don't be stopped by the "if you can't define and measure it, I don't have to pay attention to it' ploy."

(Note: this comment was cut and pasted in here on 25nov09 but didn't show up for some reason, so I am re-entering it on 4dec09. KAK)]]> Kim Kastens 1259201880 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3642 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3643
First is that the value of a number depends on the context.

You allude to this in a number of places, but I think your Mercalli Intensity data puzzle is a particularly strong example of context. Some regard intensity as unimportant in the age of seismometers and magnitudes, but intensity is more important that magnitude for analyzing the spatial effects. As someone who lives and teaches in southeastern North Carolina, the local Mercalli Intensity from the 1886 Charleston earthquake is more relevant than a magnitude estimate.

Second is the limitation of numbers.

In my first statistics course, the first thing we were told was “The purpose of statistics is insight, not numbers.” Over time, I have come to realize that this is true of the application of all mathematics to science. E = mc**2 is a famous equation, but what is important about it is the relationship of energy and mass, not the equation itself (or any particular calculation using it) .

When math or numbers can be used, they are very powerful tools, but it’s a mistake to think that they are always valuable. About 100 years ago, geologists recognized the Grandfather Mountain Window in North Carolina as a structural feature demonstrating older rocks had moved over younger rocks in the Appalachians. There was nothing numerical about this, but it remains an important insight. Further and related to the first point, is that we can seldom get a worthwhile outcome by trying to sum up a complex situation with a single number.

What we commonly need to keep in mind in geology was well expressed by John Tukey: “Far better an approximate answer to the right question, which is often vague, than an exact answer to the wrong question, which can always be made precise.”
]]> Martin Farley 1259616120 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3643 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3645
Your vivid example of the Grandfather Mountain Window as a demonstration that older rocks had moved over younger rocks is an instance of insight coming from spatial reasoning. It seems to me that spatial reasoning often yields insights without recourse to numbers. Spatial insights in geosciences can often by refined by making them quantitative (how much older were the older rocks? how far did the older rocks move?), but the seminal insight came from thinking about spatial attributes (position/configuration/trajectory), not from thinking about mathematical attributes. ]]> Kim Kastens 1259929740 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3645 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3646
(from Robin McKie, 8 nov 09, "Is man on course to cause the sixth extinction?", The Observer, http://www.guardian.co.uk/environment/2009/nov/08/humans-sixth-extinction)]]> Kim Kastens 1259930280 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3646 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3650
Steve's take on this was: "First, make better observations. You can't manage for something until you can measure it."

Biodiversity can't be well measured; therefore you can't manage for biodiversity. The existing measures are complicated, labor-intensive, require lots of time from lots of experts, and thus don't scale up well. And therefore you can't set targets, you can't reward actors who are doing well or penalize actors who are behavior poorly. ]]> Kim Kastens 1260330300 http://serc.carleton.edu/earthandmind/posts/realitytonumber.html#post3650