Saturday, August 3, 2013

The beauty of armchair science

Education experts have long assumed that the best way to engage students is to make learning as hands-on as possible. The subject that most legitimately lends itself to this is science. Hands-on science--i.e., science experiments--would seem the perfect way to get students thinking scientifically and seeing the excitement of real-life hypothesis testing. Not to mention the excitement of Bunsen burners and explosive reactions.

The main argument that skeptics have leveled against hands-on science concerns elementary school students: they aren't "little scientists" but novices who need a strong foundation in content before their lab experiences can be meaningful and memorable.

In terms of the broader discipline, of course, experiments and knowledge go hand in hand: labs are essential for the advancement of science. But are they essential for learning what's already been empirically established? And is lab-based learning necessarily more fun and engaging than learning from teachers and textbooks?

Labs, after all, can be a real headache. Measurements can be slow and tedious; many things can go wrong; results often don't make sense; some procedures involving long periods of standing, bending over, and careful monitoring. Different people have different levels of tolerance, and many students end up hating the lab component of courses they otherwise find interesting.

A friend of mine recently described to me her favorite college science course--in fact, one of her favorite courses of all. It was a class focused entirely on the psycho-neurology of the flatworm, run entirely as a seminar. First the professor would present some general topic in psychology or neurology; then he'd extend it to the flatworm and pose a few questions, soliciting various hypotheses from students.

He'd then ask them: "How would you set up an experiment to test that?"

The students would flesh out the experimental design.

Did they then go out and perform the experiment? Nope. Instead the professor would say: "That exact experiment just happens to have been done, and here's what they found."

"It was great," my friend told me. "We went through all the interesting steps in thinking through the experiment without actually having to do it!"


Anonymous said...

Very true. In addition, to the extent that the hands-on experience is valuable for K-8 students, I think that showing them some basics through observation goes a lot farther than experiments do. Especially for kids whose home lives don't provide any observation of the natural world in an organized way. I have found kids who don't realize, for example, that trees started out as little seedlings. Why would they? at 6, they haven't been around long enough to see that happen. Also, kids who don't realize that some birds fly south and other don't. Kids who have no sense of where food comes from. And so on. These can be taught very efficiently through guided observation, hopefully not too far from the school building. And field trips should focus on this aspect of science too.

ChemProf said...

Experiments can be really helpful, but the most helpful for learning are usually guided observations. Even in college, this is often the case (although the observations can look different). For a long time, we'd struggled with teaching gas laws to students, who didn't have any intuition about how gases behave under different conditions. Adding a very simple lab where students observed the pressure of air in a gas tight syringe (so they could change the volume easily) made those problems disappear. But having a "discovery" lab where students flailed around blindly (and that's what is often meant by lab experiences in K-12) wouldn't have had the same impact.

Auntie Ann said...

As a physics major and later in engineering, I never enjoyed labwork. When working on some of the more expensive equipment (like a low-energy particle accelerator,) I was always afraid I'd break it. With the exception of a couple labs during my waves class, most were forgettable.

I don't remember ever coming to any realization during lab work, nor did I need the tactile experience to understand most of the concepts. With physics, much can be grasped perfectly well in the abstract or through every-day experience.

For K-8, some things a kid should do:

-- Look at various things under a microscope, sometimes with dyes. Cells, both plant & animal. Crystals, salt, sugar, etc. Pond water with small organisms. Every-day items: hair, cloth, paper, pencil lead, wood, etc.

-- Do acid/base experiments.

-- Basic battery & current experiments. Completing/breaking a circuit.

-- Gravity experiments: dropping, pendulum, etc.

-- Weather observation; during one day, during seasons.

-- Star charting to see change during year.

-- Observations of the phases of the moon.

-- Usually get a shot at least one partial solar eclipse every few years. For that one I love to walk under a tree; the little gaps between the leaves act as pin-holes, and the ground becomes covered with the crescent of the sun.

-- Grow a plant from a seed.

-- Some cooking science: yeast, baking soda, caramelization, etc.

-- Then just measuring things using different tools: mass, length, volume, time.

Anonymous said...

Right, Chemprof. The chemistry lab experiments we did in HS were totally scripted; we did not design experiments (though we did have to figure out how to represent the results in terms of standard chemical notation). I think the real point was to get us comfortable with using lab equipment so it wouldn't trip us up in college. But we did not really learn anything new in the lab, we just demonstrated to ourselves material we had learned in class.

ChemProf said...

Chemistry is different from physics, in part because a chemist should have a set of skills as well as theoretical knowledge. If you can't prepare a standard curve or do a titration, you aren't really a chemist. It is actually a problem in my field that the practical has been undervalued at a lot of schools -- it is easier to hand the sample to the TA when there are hundreds of students, but then students graduate without the hands on experience they should have.

I like your K-8 list!