Why science definitions matter: a response to the NCSE’s Misconception Mondays

Dear fellow scientists and science educators: may I suggest the time has come to work together to standardize the major terminology of our field?  I don’t mean the terminology of specific disciplines, I am getting at the fundamentals here: what is science, and how do we effectively and efficiently communicate what a hypothesis, law, and theory are?

I am writing this post because I read with some dismay the recent National Center for Science Education’s blog Misconception Mondays: Hypotheses, Theories, and Laws, Oh My! by Stephanie Keep.  I encourage my readers to read her blog post and form your own opinions.  I want to be clear from the beginning that this is nothing personal about Stephanie Keep — her post simply caught my attention and serves as a spring board for discussing what I read and hear all too often from many of my colleagues.

The take home message from Keep’s post is this: it doesn’t matter what labels we give concepts in science, so long as science is being taught.  In essence, don’t get bogged down in semantics and lose the forest for the trees — it is more important that students understand the science.  At face value, this seems reasonable: don’t be pedantic be practical.

On deeper reflection, however, this attitude (an attitude shared by many in the sciences) is troublesome, because definitions and the meanings we attach to words do matter, especially for students and the public who vote on science issues.  Keep says:

People—especially scientists—like firm definitions. Science is full of technical terms that we learn to master (or learn to quickly look up on the Internet), and thanks to a mixture of precedent and state standards, many teachers keep making kids learn definitions for theory, law, and hypothesis in the introductory weeks of a new class. I’m not suggesting that kids shouldn’t learn what a hypothesis is—of course they should! Forming and testing hypotheses are fundamental parts of any scientific endeavor. But I am suggesting that we be willing to admit that there is often no good reason why something is called a law vs. a theory, or a hypothesis vs. a theory—and that’s okay.

But therein lies the fundamental problem with this approach — not just Keep’s approach, but, I would argue, the approach so many of us have been taught to take.  How can you teach a student how to test a hypothesis if you simultaneously tell them that we can’t tell if it’s a hypothesis or a theory?  These definitions do matter.

Something else is troublesome in Keep’s statement that, “many teachers keep making kids learn definitions for theory, law, and hypothesis in the introductory weeks of a new class.”  In any discipline, you learn what it is and how it works in the beginning so that you have a common language through which to teach and make sense of the core material.

If we are charged with doing science and with educating the public about science, shouldn’t we able to say: here is what science is, here are it’s limits, and here’s how the toolkit works?  Especially at the beginning of a class?  As scientists and science educators, we seem on the whole to be so circumspect about this because, I suspect, we appreciate that science is not about certainty but about probability.  Therefore, we are loathe to say we have a concrete definition because we fear that what we convey is an absolutism rather than messy reality.  Believe me — I understand and appreciate wanting to avoid teaching our students that science = unassailable truth.  But if this is a fear of looking too authoritarian, in my opinion, it has led to much confusion both among ourselves and the public at a time when science is under attack.

Dear scientists and science educators: it is okay to have firm definitions that define and describe what we do, and we need to give ourselves permission to be okay with that.  It is no longer okay for us to say to students, in essence, we can’t really describe or define what it is we do precisely, but you’ll know it when you see it.

It would be arrogant and presumptuous on my part to suggest I have the definitive answer or definitions for what we do, nor do any of us work and teach in a vacuum — much of what I teach my students is cobbled together from what I have found works for me as an instructor (borrowed and morphed from many gifted individuals), particularly the approach of a former graduate mentor, Dr. Ron Toth at Northern Illinois University.

But I would like to start a conversation about fundamentals.  Surely, science as a discipline is not an amorphous thing.  I suspect most of us would define it as a tool for understanding the natural world.  Many of us test hypotheses – these are predictive statements that can be tested and falsified which guide our research.  We often test our hypotheses under an explanatory umbrella we call a theory.  As an example, a paleontologist might test the relationships of various dinosaurs (a hypothesis called a phylogeny) using data collected from fossils, working under the explanation that they are closely or distantly related through common ancestry (a theory called biological evolution).

Laws, I will admit, often stick in many of our craws.  I have come to see scientific laws as testable descriptions of repeatable phenomena or processes.  If we define scientific laws in this way, we are now more clear about what should qualify.  For example, in her essay, Keep says,

Have you ever noticed that most of the “laws” in science tend to be in the physical sciences and astronomy? There aren’t a lot of “laws” in biology—in fact, I can’t think of any aside from Mendel’s Laws. Why is that? Is it because biology is a “soft science” while physics and astronomy are “hard sciences”? Not at all. It’s because people in those fields really liked the term “law.” No, really. That’s pretty much it.

I would argue that we do have laws in all the branches of science, we just don’t always call them that.  If a scientific law is a repeatable phenomenon or process, Genetic Dogma (DNA is transcribed and translated by RNA into proteins) is a law — it happens continuously in all living things, always the same — a repeatable phenomenon or process.  Natural Selection is a Law — all individuals vary, more individuals in a population are born than can survive, and those with variable traits that allow them reproduce viable offspring are “selected.”  Look at any population in the living world, and this process is on-going and repeatable.  How about calling the Cell Theory, the Cell Law?  After all, that living things are made of cells is pretty much a repeatably observable phenomenon.

This works for me and for teaching my students, but I am not suggesting I have the market cornered on this definition.  Rather, my point here is that when we have a clear definition, we can more easily comprehend what we are communicating to one another and to our students.  If I am testing a hypothesis, you and others know I am probably working under an explanation, a theory.  If I am testing a law, you and others know that if I find variation or the phenomenon does not repeat, I may be in a position to reject or modify that law.

We need to have this conversation because definitions do matter in science.  What you call something does matter, especially when you need it to convey a particular set of qualities.  True, there will always be exceptions to the definitions and the natural world is messy, but don’t let perfection be the enemy of progressScience is and should be definable — we don’t just know it when we see it.

I welcome any constructive feedback and ideas from all of my colleagues as to how we can and should move forward.  I want to thank Stephanie Keep for sparking this conversation.

For those who don’t know and who might be interested, I have outlined and explained my own approaching to teaching science and evolution.