<p>The origin of this adage/joke is probably lost for ever... However, I've finally managed to track down some written sources containing various versions of it! Here is a summary of what I've found so far, I'll edit if I find more.</p>
<p>In the book <em>Start collecting rocks and minerals</em> (which can be <a href="https://archive.org/details/startcollectingr00srog" rel="nofollow noreferrer">borrowed online</a> at the Internet Archive), geologist LeeAnn Srogi states (p. 100):</p>
<blockquote>
<p>Scientists love to argue. If you show a rock to ten geologists,
they'll tell you ten different stories about how it formed.</p>
</blockquote>
<p>A similar version can be found in <a href="https://newsday.co.tt/2022/02/24/why-trinidad-rocks-excite-geologists/" rel="nofollow noreferrer">an article</a> from Trinidad and Tobago <em>Newsday</em>:</p>
<blockquote>
<p>Put ten geologists in the same room to examine a rock sample and you
may get ten different opinions about what type of rock it is and its
origin.</p>
</blockquote>
<p>In an issue of <a href="https://doi.org/10.1190/tle38050402.1" rel="nofollow noreferrer">Geophysics Bright Spots</a>, a king of editorial published in <em>The Leading Edge</em>, the following can be read:</p>
<blockquote>
<p>Among geoscientists, there is a provocative joke: “Ten geologists in
front of an outcrop generally come up with 11 different
interpretations, because one of them changes their mind.” This holds
even more so for the interpretation of subsurface structures from
seismic images.</p>
</blockquote>
<p>In <a href="https://highway8a.blogspot.com/2010/07/where-it-all-began.html" rel="nofollow noreferrer">a blog post</a>, I've found a geologist stating:</p>
<blockquote>
<p>One thing that geologists are sure of is the existence and viability
of other ways — this idea is technically referred to as &quot;<a href="https://www.thoughtco.com/geological-thinking-1440872" rel="nofollow noreferrer">multiple
working hypotheses</a>,&quot; and it's sometimes overstated as, &quot;if ten
geologists mapped the same area, you'd end up with at least ten
different maps.&quot;</p>
</blockquote>
<p>I've encountered a reference to a submitted paper entitled &quot;The Scientific Basis for Stratigraphic Inversion&quot;, written by Cross and Lessenger. I could not find a published version of said paper, but managed to dig out the <a href="https://web.archive.org/web/20070701020829/http://strata.geol.sc.edu/PDF-Files/Simulations/SciBasisStratigraphicInversionCrossInPress.pdf" rel="nofollow noreferrer">submitted version</a> thanks to the Wayback Machine. The introduction begins with:</p>
<blockquote>
<p>Ten geologists observe an outcrop of strata and produce eleven
interpretations (one geologist had a change of mind), and all
interpretations are considered equally valid. This common perception
has the uncomfortable weight of truth despite the obvious
exaggeration, and is the basis for jokes about differences among the
geoscience disciplines.</p>
</blockquote>
<p>In an <a href="https://rock.geosociety.org/gsatoday/archive/5/3/pdf/gt9503.pdf" rel="nofollow noreferrer">issue of <em>GSA Today</em></a>, geologist J. David Rogers states:</p>
<blockquote>
<p>There are geologists and there are geologists: engineering geology is
a tremendously subjective art. Put three geologists in a room and
you’ll likely elicit three answers.</p>
</blockquote>
<p>This <a href="https://www.unsw.edu.au/science/our-schools/bees/student-life-resources/honours/honours-projects/palaeo-earth-water-geoscience/stromatolites-35-billion-year-old-dresser-formation" rel="nofollow noreferrer">science project synopsis</a> at UNSW Sidney begins with:</p>
<blockquote>
<p>Ask five geologists what the oldest evidence for life on Earth is and
you’ll get five different answers.</p>
</blockquote>
<p>In a <a href="https://www.pressherald.com/2015/07/23/underneath-oregon-notes-from-the-underground/" rel="nofollow noreferrer"><em>Times Record</em> article</a>, geologist Courtney Cloyd is quoted saying:</p>
<blockquote>
<p>“It’s really detective work, what geologists do — interpreting what
you see,” Cloyd said. (Not that they always agree, he added later:
“For every five geologists, you get at least seven opinions.”)</p>
</blockquote>
<p><a href="https://www.salient.org.nz/post/hitchhiker-s-guide-to-the-bottom-of-the-world" rel="nofollow noreferrer">This article</a>, written by two earth scientists after a mission in Antarctica, goes wild on the numbers!</p>
<blockquote>
<p>In theory, our target rocks are easy to identify; lightly coloured,
glacially-smoothed cobbles perched on a dark, sharply-angled bedrock
surface. They have absolutely no business being there! In reality, if
you ask five geologists to identify a rock in Antarctica, you’ll hear
twenty different opinions.</p>
</blockquote>
<p>Finally, <a href="https://www.jstor.org/stable/3838763" rel="nofollow noreferrer">this research</a> published in <em>The Journal of Higher Education</em> has this interesting passage:</p>
<blockquote>
<p>Members of a couple who are both structural geologists illustrate the
way that academic conventions build differences of opinion into a
routine part of their day-to-day work life. Pointing to elements of
their academic training that socialized them to entertain multiple
hypotheses, she noted: &quot;In our discipline, you see it as good science
to be as argumentative as possible without bringing personality into
it... If you have five geologists on a field trip, you will have ten
hypotheses to explain it at the end of the trip.&quot;</p>
</blockquote>
<p>Some remarks based on these 10 versions of the story:</p>
<ul>
<li>They involve geologists in a great diversity of activities: rock identification/formation, geological mapping, outcrop interpretation, engineering geology...</li>
<li>There are 5 versions with <span class="math-container">$X = 10$</span>, 4 with <span class="math-container">$X = 5$</span>, and 1 with <span class="math-container">$X = 3$</span>.</li>
<li>5 versions have <span class="math-container">$Y = X$</span> (although one says &quot;at least&quot;), then it's either <span class="math-container">$Y = X + 1$</span> (2 versions), <span class="math-container">$Y = X + 2$</span> (1), <span class="math-container">$Y = X + 5$</span> (1) or <span class="math-container">$Y = X + 15$</span> (1).</li>
</ul>

CC BY-SA 4.0
2024-11-11T19:18:19.160Z
This brings back memories. :-) Intellectual competition with some humor.
Fred
CC BY-SA 4.0
2024-11-12T08:50:16.717Z
@Universal_learner I've managed to find five more, with different numbers! Check my edit if you're interested in the topic.
Jean-Marie Prival
CC BY-SA 4.0
2024-11-12T08:51:00.887Z
@Fred I really enjoyed reading those! I've even managed to dig out more versions, see my edit.
Jean-Marie Prival
CC BY-SA 4.0
2024-11-11T13:38:49.443Z
2024-11-12T08:49:07.813Z
2024-11-12T08:49:07.813Z
Jean-Marie Prival
<p>I once heard (read? I can't remember) an adage which stated something like this (my recall):</p>
<blockquote>
<p>Show an outcrop to X geologists, you'll end up with X different
interpretations about its formation.</p>
</blockquote>
<p>(I wonder if it was not even Y interpretations, with Y &gt; X.)</p>
<p>I have a hard time finding this online with such generic keywords... As there are several geologists here, I'd like to ask:</p>
<ul>
<li><strong>What is the exact wording of this adage?</strong> (or let's say the most commonly found in the literature, written sources welcomed!)</li>
<li><strong>Who first said/wrote it</strong>, if this can ever be tracked?</li>
</ul>

CC BY-SA 4.0
2023-08-15T18:58:06.360Z
someone who doesn't actually know anything about geology?
John
CC BY-SA 4.0
2023-08-15T19:47:31.857Z
@John You mean you disagree with this statement? I kind of agree with it. I just read a 1993 paper where the authors summarize one century of diverse interpretations for the very same outcrop, before giving their own. A 2023 paper has just proposed yet another interpretation... Of course all outcrops are not that complex, some are pretty straightforward to understand, but to me field geology is a discipline which still leaves much room for a diversity of interpretations.
Jean-Marie Prival
CC BY-SA 4.0
2023-08-16T03:49:28.660Z
You could say the same for any doctor diagnosing a disease, any archeologist interpreting a site, or astronomer reconstructing a stellar history, the fact that when you have limited data some difficult examples exist does not undermine the discipline.
John
CC BY-SA 4.0
2023-08-16T04:04:56.283Z
I've heard variations of the adage over the past 30-40 years. Not always in relation to outcrop, but also interpretations of lines of drilling & other things that are open to interpretation by geologists. It's usually of the form *Show an outcrop to X geologists, you'll end up with Y different interpretations about its formation*, where Y is usually 1 or 2 greater than X, but sometimes 3 or 4. I've mostly heard it as a facetious joke or comment. Sometimes geologists have said it about geologists & on other occasions mining engineers have said it about geologists. I don't recall having read it.
Fred
CC BY-SA 4.0
2023-08-17T07:44:49.693Z
@John Of course, that was not my intention.
Jean-Marie Prival
CC BY-SA 4.0
2023-08-17T07:46:13.080Z
@Fred Thank you for this testimony! I guess the origin will be hard to track down, especially if it has only been an oral tradition...
Jean-Marie Prival
CC BY-SA 4.0
2024-11-11T09:44:18.523Z
@Universal_learner Thanks for your effort.
Jean-Marie Prival
<terminology><history-of-science>
Source of an adage about geologists and their various interpreatations of outcrops
Jean-Marie Prival
# Source of an adage about geologists and their various interpreatations of outcrops

(Asked by: username_0 on 2023-08-15)

I once heard (read? I can't remember) an adage which stated something like this (my recall):

> Show an outcrop to X geologists, you'll end up with X different
> interpretations about its formation.

(I wonder if it was not even Y interpretations, with Y > X.)

I have a hard time finding this online with such generic keywords... As there are several geologists here, I'd like to ask:

* **What is the exact wording of this adage?** (or let's say the most commonly found in the literature, written sources welcomed!)
* **Who first said/wrote it**, if this can ever be tracked?

**Tags:** terminology, history-of-science

> **Comments:**
> **username_1**: someone who doesn't actually know anything about geology?  
> **username_0**: @username_1 You mean you disagree with this statement? I kind of agree with it. I just read a 1993 paper where the authors summarize one century of diverse interpretations for the very same outcrop, before giving their own. A 2023 paper has just proposed yet another interpretation... Of course all outcrops are not that complex, some are pretty straightforward to understand, but to me field geology is a discipline which still leaves much room for a diversity of interpretations.  
> **username_1**: You could say the same for any doctor diagnosing a disease, any archeologist interpreting a site, or astronomer reconstructing a stellar history, the fact that when you have limited data some difficult examples exist does not undermine the discipline.  
> **username_2**: I've heard variations of the adage over the past 30-40 years. Not always in relation to outcrop, but also interpretations of lines of drilling & other things that are open to interpretation by geologists. It's usually of the form *Show an outcrop to X geologists, you'll end up with Y different interpretations about its formation*, where Y is usually 1 or 2 greater than X, but sometimes 3 or 4. I've mostly heard it as a facetious joke or comment. Sometimes geologists have said it about geologists & on other occasions mining engineers have said it about geologists. I don't recall having read it.  
> **username_0**: @username_1 Of course, that was not my intention.  
> **username_0**: @username_2 Thank you for this testimony! I guess the origin will be hard to track down, especially if it has only been an oral tradition...  
> **username_0**: @Universal_learner Thanks for your effort.  

---

## 1 answers

### Answer by username_0 on 2024-11-11. Score: 2

The origin of this adage/joke is probably lost for ever... However, I've finally managed to track down some written sources containing various versions of it! Here is a summary of what I've found so far, I'll edit if I find more.

In the book *Start collecting rocks and minerals* (which can be [borrowed online](https://archive.org/details/startcollectingr00srog) at the Internet Archive), geologist LeeAnn Srogi states (p. 100):

> Scientists love to argue. If you show a rock to ten geologists,
> they'll tell you ten different stories about how it formed.

A similar version can be found in [an article](https://newsday.co.tt/2022/02/24/why-trinidad-rocks-excite-geologists/) from Trinidad and Tobago *Newsday*:

> Put ten geologists in the same room to examine a rock sample and you
> may get ten different opinions about what type of rock it is and its
> origin.

In an issue of [Geophysics Bright Spots](https://doi.org/10.1190/tle38050402.1), a king of editorial published in *The Leading Edge*, the following can be read:

> Among geoscientists, there is a provocative joke: “Ten geologists in
> front of an outcrop generally come up with 11 different
> interpretations, because one of them changes their mind.” This holds
> even more so for the interpretation of subsurface structures from
> seismic images.

In [a blog post](https://highway8a.blogspot.com/2010/07/where-it-all-began.html), I've found a geologist stating:

> One thing that geologists are sure of is the existence and viability
> of other ways — this idea is technically referred to as "[multiple
> working hypotheses](https://www.thoughtco.com/geological-thinking-1440872)," and it's sometimes overstated as, "if ten
> geologists mapped the same area, you'd end up with at least ten
> different maps."

I've encountered a reference to a submitted paper entitled "The Scientific Basis for Stratigraphic Inversion", written by Cross and Lessenger. I could not find a published version of said paper, but managed to dig out the [submitted version](https://web.archive.org/web/20070701020829/http://strata.geol.sc.edu/PDF-Files/Simulations/SciBasisStratigraphicInversionCrossInPress.pdf) thanks to the Wayback Machine. The introduction begins with:

> Ten geologists observe an outcrop of strata and produce eleven
> interpretations (one geologist had a change of mind), and all
> interpretations are considered equally valid. This common perception
> has the uncomfortable weight of truth despite the obvious
> exaggeration, and is the basis for jokes about differences among the
> geoscience disciplines.

In an [issue of *GSA Today*](https://rock.geosociety.org/gsatoday/archive/5/3/pdf/gt9503.pdf), geologist J. David Rogers states:

> There are geologists and there are geologists: engineering geology is
> a tremendously subjective art. Put three geologists in a room and
> you’ll likely elicit three answers.

This [science project synopsis](https://www.unsw.edu.au/science/our-schools/bees/student-life-resources/honours/honours-projects/palaeo-earth-water-geoscience/stromatolites-35-billion-year-old-dresser-formation) at UNSW Sidney begins with:

> Ask five geologists what the oldest evidence for life on Earth is and
> you’ll get five different answers.

In a [*Times Record* article](https://www.pressherald.com/2015/07/23/underneath-oregon-notes-from-the-underground/), geologist Courtney Cloyd is quoted saying:

> “It’s really detective work, what geologists do — interpreting what
> you see,” Cloyd said. (Not that they always agree, he added later:
> “For every five geologists, you get at least seven opinions.”)

[This article](https://www.salient.org.nz/post/hitchhiker-s-guide-to-the-bottom-of-the-world), written by two earth scientists after a mission in Antarctica, goes wild on the numbers!

> In theory, our target rocks are easy to identify; lightly coloured,
> glacially-smoothed cobbles perched on a dark, sharply-angled bedrock
> surface. They have absolutely no business being there! In reality, if
> you ask five geologists to identify a rock in Antarctica, you’ll hear
> twenty different opinions.

Finally, [this research](https://www.jstor.org/stable/3838763) published in *The Journal of Higher Education* has this interesting passage:

> Members of a couple who are both structural geologists illustrate the
> way that academic conventions build differences of opinion into a
> routine part of their day-to-day work life. Pointing to elements of
> their academic training that socialized them to entertain multiple
> hypotheses, she noted: "In our discipline, you see it as good science
> to be as argumentative as possible without bringing personality into
> it... If you have five geologists on a field trip, you will have ten
> hypotheses to explain it at the end of the trip."

Some remarks based on these 10 versions of the story:

* They involve geologists in a great diversity of activities: rock identification/formation, geological mapping, outcrop interpretation, engineering geology...
* There are 5 versions with $X = 10$, 4 with $X = 5$, and 1 with $X = 3$.
* 5 versions have $Y = X$ (although one says "at least"), then it's either $Y = X + 1$ (2 versions), $Y = X + 2$ (1), $Y = X + 5$ (1) or $Y = X + 15$ (1).

> **Comments:**
> **username_2**: This brings back memories. :-) Intellectual competition with some humor.  
> **username_0**: @Universal_learner I've managed to find five more, with different numbers! Check my edit if you're interested in the topic.  
> **username_0**: @username_2 I really enjoyed reading those! I've even managed to dig out more versions, see my edit.  

---

