velocity, vectors, and vocabulary

Let me start off with this- I don’t think that vocabulary and conceptual understanding are mutually exclusive. But a friend’s facebook post asking why freshmen need to know velocity and vectors got me thinking about vocabulary vs conceptual understanding. When is the vocabulary essential and when is it, well, not?

A student can conceptually understand the difference between speed and velocity without ever knowing the term “vector”. When I’ve taught physics, it’s just been “velocity is speed and direction”, and we used designators such as “5 m/s north” or “10 m/s south”. We did also use positive vs. negative, but always specified (“left is the negative direction” or “south is the negative direction”). We did also talk about magnitude and direction with forces, but I rarely used the term “vector” with my freshman physics classes. (I might have mentioned “vector” in passing once or twice. And maybe a student even brought it up, because my students like to use science-y words to sound “smart” in class.)

In chemistry, we’ve recently been working on electron configuration and the quantum model of the atom. But I don’t think I’ve yet mentioned the term “quantum model” with my students (we did introduce “Bohr model” to have a handle on what that thing with the electrons in rings is called). This year, we also explicitly took out vocabulary such as “Aufbau principal”, “Hund’s rule”, and “Pauli exclusion principal”, because our team agreed that we didn’t care that students could use the correct names for the rules but rather wanted to focus on whether students could shown how an orbital diagram (Aufbau diagram, apparently) is filled correctly. I actually don’t know exactly what the Aufbau principal or Hund’s rule refer to specifically, but I can draw an orbital diagram and explain what it’s showing. Why would I expect my students to know exactly what these rules are? And does it tell me anything about their conceptual understanding if they can recite the rule? My experience from teaching physics was that students could often refer to Newton’s laws (from their middle school science classes) but still had some naive conceptions about how forces and motion work (e.g., that there must be a force on an object to keep it moving, despite being able to cite Newton’s first law).

So I’m wondering. What does the vocabulary add to the understanding? Am I doing my students a disservice by not using the “official” terms with them, when if they take a college chemistry course their professors will almost certainly refer to the Aufbau principal, Hund’s rule, and the Pauli exclusion principal? Often, principals, rules, and laws in particular are named after the men (almost always men) who are attributed with discovering them, but then what message does that convey about science and discovery? Science in particular is heavy with white male names, and I wonder what that tells my non-white, non-male students about whether they are welcome in science. (Also, I’m sure there are instances where non-white and/or non-male scientists made the same discoveries in parallel, but the discovery is attributed to the white, male scientist. I wish I knew more about these instances, because it would be nice to bring up in class sometime.) Is my class somehow less rigorous because I don’t often include names of rules? When we were working on gas relationships, I never used the terms Boyle’s Law, Charles’s Law, or Gay-Lussac’s Law (and apparently the P-T relationship shouldn’t be called Gay-Lussac’s law anyway, and is rather Amontons’ Law? ). And even now, I have to think a little carefully about which relationship goes with which name, even though I know that pressure/volume are inversely related and volume/temperature and pressure/temperature are directly related. (Of course, we didn’t ask them to do any calculations with the gas laws, so maybe that’s another reason why I never bothered giving the names to each of these laws.) So if I, as someone who is fairly well-versed in chemistry, don’t remember all the names of all of the laws, but I can figure out the relationships, do I need to teach my students the names of these things too?

Is it ok to not hold students accountable for vocabulary terms as long as they can demonstrate understanding of the concepts? When is vocabulary important and when is it not? I still make sure my students can use terms like protons, neutrons, electrons, and ionization energy, electronegativity, atomic radius correctly (can you tell we’re working on periodic trends soon?). I don’t necessarily care if they know the terms “Coulombic attraction” or “effective nuclear charge” as long as they can explain the reason for the trend accurately.

Vocabulary is something that I find myself conflicted about as a relatively new teacher. I had to learn all these terms, so they must be important! But do they tell me anything about student understanding? Does it help the student communicate their understanding? Or is it just “one more thing” that students have to wrap their brains around and spit back at me? And if they just cram in all the vocabulary, does that mean they know what’s happening?

I realize that my blog posts tend to have a lot of unanswered questions. But that’s just because these are the things that I’m wondering about as I go through my planning, teaching, reflecting. And I have a lot of wonderings and very few answers, but I think that’s ok. It took me a long time to be ok with unanswered questions (graduate level research did not agree with me when I could not find the answer to the research question), but I think this is a stance I need to be able to process the world of teaching.

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