Knowing the Name of Something

"Knowing the name of something doesn't mean you understand it." - Richard Feynman

My blog is usually for any teacher, but this one has a much more science teacher focus.  You might still get something out it if you don't teach science, but expect it to be more about teaching science.

This week, I taught Archimedes' Principle, which explains why some things float and others sink.  It's one of my favorite things to teach because of the conversation I get to have with each of my 8th-grade classes.  Here's how it goes.

• I hold up a golf ball and ask if it will float or sink when I put it in water.  Those who have apparently never golfed think it will float.  I drop it in the water, and it sinks.
• I hope up a practice ball that is the same size, but the interior is foam (I've never figured out why they exist as practicing with them would not be the same, but I digress).  They're on to me, so they know that one will float.
• I ask why.  First I get the cheap answers, like "because they are made of different materials" and "because one has more air in it."  I say, "Well, sure, but the question I'm asking is why does that matter?"  
• At some point, a kid who has listened in elementary school says either the word "density" or "buoyancy."  Now, we're cooking.  I respond with, "You say density like you know what it means.  Do you."  Chagrinned expressions abound when they say, "Well, actually, no."
• I tell them that I am going to explain the reason things float or sink without using the word density and that I will then bring it around to density in the end because, while they are not wrong, I want them to understand what that means, not just know the right word.

While this is the most explicit example of this phenomenon of the year, it happens about three times a week in smaller ways.  Students have learned that if they say the word the teacher is looking for, they'll be told "good job" and moved away from.  They know the standard textbook definitions of matter ("anything that takes up space and mass") and energy ("the ability to do work"), which are stupid definitions.  Those definitions aren't wrong, but they certainly aren't helpful.  

Science teachers, we have to slow down and take the time to ask students to elaborate.  When they give the right word, it does not always mean they know what they are talking about.  We have to find out which it is.  If I did not engage in this Archimedes' Principle conversation, students would go on throughout their whole lives knowing the right word to say without understanding the role density plays in floating.  While you might not think that matters, I'm not teaching science if I am only teaching words and not complete ideas.  

This is where it helps to have students understand that you are the expert in the room.  I know the recent "guide on the side rather than sage on the stage" movement has taught you that kids can discover everything they need to know, but they can't.  They can float things and sink them all they want and come to very wrong conclusions, just as people did for thousands of years before Archimedes.  They can go on thinking heavy things fall faster than light ones just as people did for thousands of years before Galileo.  They need you to explicitly tell them things, even if you decide they should experience it afterward.  I have students build aluminum foil boats to apply Archimedes' Principle, but I would never dream of having them do that without the direct instruction first and follow-up reflection on which boats held the most weight after.  

Richard Feynman was one of the great physics teachers of the twentieth century.  His quote above was his philosophy of education.  At one point, he went as far as to say it didn't matter at all whether students knew the name of something; they only needed to understand it, but he ended up reversing that decision because he said people would ask him about something by naming it, and when he told them he didn't know about it they would be shocked and start explaining it, only for him to realize he did know about it but hadn't recognized his name.  In his book The Pleasure of Finding Things Out, he talks a lot about his father and the ways in which he taught young Richard to view the world.  His father was the one who told him how knowing the name of something wasn't the same as knowing about the thing.  That set him on the path to becoming the physicist and professor he eventually became.  Had it not been for his very-much-non-scientist dad, Richard Feynman might not have been the amazing scientist that he was.  

In your classroom, they are students, and you are the teacher.  Be the teacher.  That means that you decide what they are capable of learning from internet research and observation and what you need to explicitly tell them.  It means that when you have them do internet research and hands-on experiences, you have to follow up with formative assessment questions to find out if they learned what you wanted them to learn.  It means you decide what level of mastery they should have to achieve before you move on.  It means you find out whether they know the name of something or whether they actually understand it.