Sunday, May 9, 2010

Fundamentals of the Empirical Approach

One of the defining characteristics of science is the use of empiricism in gaining new knowledge. While empiricism is an exceedingly broad topic that would take books and books to explain, on a simple level it is the practice of using what we observe as the basis of finding things out, as opposed to what we think or reason out as the basis of finding things out. While it is no guarantee, but if you are a physicist (or other comparable scientist) then most likely you take an empirical approach to your work, and how you view the world. Despite this many physicists (and scientists) fail to use an empirical approach in some of the most simple and basic (and critical ) circumstances.

One of the best lessons I learned about empiricism and how to look at things I learned from Dr. Jean-Francois Van Huele. When I was in his modern physics class at BYU he did a rather interesting exercise with the class. He put up a graph similar to the one below, that had no labels or title and asked us, "What do you see?"
One student immediately responded with "Well that's a graph of the emission lines from [thing that the graph was showing]." and his response was, "How do you know that? Where on the graph does it say that?" After a short silence he continued, "Describe the graph, describe what you see." Then after another silence one student shouted out, "I see a line." Another said, "I see bars on the line." And another said, "I see a box around the whole thing." And then the students began to describe the basic structure of the line, i.e. there were some spikes in the line, it had a regular pattern, the line was slightly curved but not too much, there were some random black dots on the graph that did not fall on the line (they were bits of dust that got photocopied onto the transparency, but the point that Dr. Van Huele was making was that it didn't matter where they came from, they were there).

When we were done describing every little line, dot and splotch that we saw on the graph Dr. Van Huele told us that in science the point in not to take someone's explanation of what is given as correct, or to assume that what we see has a specific meaning, but that when presented with something, even a graph in a published paper, we should look at it on a basic level and learn to interpret it based on what we see, and not on what we think it tells us.

Since then I have always looked at graphs, charts and data differently. There have been a number of times when someone has presented a graph and said, "This graph clearly shows [fill in the blank]." But I look at it and say, "No it doesn't." I have seen this in astronomy papers, in papers on global warming (both for and against), in news articles and generic "studies". Unfortunately I have found that not all scientists take such a fundamental approach to empiricism, and in my opinion if they did, then it would prevent a lot of bad science.


  1. Great reminder, both of Professor van Huele and empiricism. I saw the same graph when I took his class in Fall 2002.

  2. Quantumleap42,

    Very interesting. I remember the first time I met Dr. Jean-Francois Van Huele at BYU he told me "You don't understand a subject until you can read textbooks on the subject and can find all the errors."

    Slightly different then what you are talking about, but it's a quote I've always remembered and to be honest: There's a lot of truth to it.

  3. I essentially agree, but experience and knowledge are very important to making such questioning meaningful. A five percent difference between two groups may be extremely important in one context, and meaningless in another. Only by getting a feel for the field can you make a such a judgment.

    I guess what I'm saying is, yes, question authority. But also keep some humility because the current group of authorities are authorities for a reason. Otherwise a person may become a self-confident know-nothing.

  4. Quantum,

    In my field of work we create a lot of graphs to represent medical and physiological data. I am sorry to say that the approach is more that of telling the reader what to find in the data that is being displayed. When it comes to publication in health care, editors like authors to tell readers what to look for in the graphs (e.g., asterix over bars represent significance). However, I think most inquiring scientific minds tend to look for something unusual in the graphs, something the authors may not have seen. This tendency comes from the discovery gene that most scientists carry (i.e., always on the look out for something new and interesting). Ciao!


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