Translator: Ilze Garda Reviewer: Peter van de Ven
I'm a high school teacher;
I'm not used to having an entire room listen to me.
(Laughter)
So, who here, when they were in school, enjoyed studying science?
Not bad.
Now, during the last week,
who here used something you learned in your physics class
during your everyday life?
OK, there are a couple, but not many.
So I think, as a teacher,
I'm not having much of an impact on my students' lives,
and that's a problem.
I'd like to start by telling you a story about Zaya.
Zaya was a student I taught in Mongolia, seven years ago.
She was 14 years old at the time.
Zaya was a quiet girl, she studied hard,
and she always had a nice word for her friends.
Zaya believed in UFOs.
Her grandfather claimed to have been abducted several times,
and had become famous for his paintings depicting the abductions.
During the time that I knew her, Zaya went to the Internet,
and she began to learn more about conspiracy theories.
Over time, she began to suspect
that the local government, the national government,
and even the world economy were being run by little green people.
This is what happens
when you take a teenager who hasn't learned to think critically,
and you give her the Internet.
So, as a world we've got some serious challenges facing us:
global warming, advances in healthcare,
and technology evolving at an increasingly rapid rate.
In order for us as a society to deal with these,
we're going to need a scientifically literate populace.
At the same time,
if you as a person can use scientific and critical thinking in your life,
you will be empowered to better understand the world.
But, as in the case of Zaya,
we, teachers, are not teaching students how to think critically.
We are not teaching students
how to use scientific ideas to make meaning in their lives.
Most of us recognize that we need to do better,
but, at the same time,
much of the conversation is focused on the wrong things.
A lot of people seem to think
that we could make kids love science and be good at science
if only we could show them
enough explosions and fascinating demonstrations.
So let's have a fascinating demonstration.
(Applause)
I've got a flask; there's a catalyst in here.
This flask contains hydrogen peroxide along with some regular dish soap.
I'll just pour that in.
And we get this cool effect here.
What's happening
is that the hydrogen peroxide is being broken apart by the catalyst,
turning into water and releasing oxygen gas.
Because there is soap in the mixture,
that oxygen gas is being captured by the bubbles,
and we are getting a whole bunch of bubbles.
During the next 10 or so minutes, this is going to continue to erupt.
Hopefully, that doesn't distract you too much
from what I'm trying to say over here.
Alright, so that's all very cool,
but does it make you curious about the world?
Does it make you wonder why the sky is blue,
or how a car engine works,
or why turtles have cool patterns on their shells?
No, not really.
I mean, asking questions like that makes you curious, but I'm not sure
that this type of demonstration is doing very much for students.
Unless we can use demonstrations
to promote curiosity or to teach critical thinking,
these demonstrations are nothing more than snake oil
in a world that needs people to learn how to think critically.
The second mistake that we're doing
is we're assuming that science is some sort of collection of knowledge.
Well, if science is a collection of knowledge,
then schools are in the business
of determining whether or not students learn this knowledge.
We have two main tools to do this.
The first of them is the multiple-choice question.
Which colour will produce the best resolution
in an optical telescope or a microscope?
There we four wrong answers and one right answer.
Which sort of power plants should we build to provide us with electricity?
There is no room for subtlety, or clarifications, or explanations.
How many chromosomes do humans have?
There is no exceptional cases, just the answer.
Which of these similarly phrased definitions
is the correct definition for energy?
It's mostly just a test of reading comprehension.
Which is the closest star?
You cannot assess a child's ability to ask the right questions,
formulate a hypothesis, conduct an experiment,
or make meaning in their lives with this multiple-choice test.
OK, so the other technique that we have is to ask science problems.
Science problems pretend to be real-life situations
in which students are supposed to apply their scientific knowledge.
Here's an example.
The mass is 5 kilograms,
the acceleration is 2 meters per second squared,
and we know that force is mass times acceleration,
so what is the force?
When students see a problem like this,
they say, "What equation am I supposed to use?
What vocabulary am I supposed to use?
What ideas am I supposed to write down on a paper?"
And they stop thinking.
These problems provide no meaningful assessment
of a child's ability to apply scientific knowledge.
They are nothing but a test
of whether or not students are able to solve this type of problem.
So, science tests are no good, right?
But so what?
The problem is that these tests are acting as gateways,
we use them to keep students from graduating from school,
we use them to let students into university, and we use them
to allow students to receive the career preparation that they need.
As a result, there is a tremendous amount of pressure
on students, on families, and on teachers
to prepare students for these tests.
We're focusing on the wrong thing, these tests are the wrong goal.
If there is any magic or meaning in science at the start of the year,
it is gone by December.
So, here's the state of things.
Science education isn't working.
We're trying explosions that are not effective,
and we're grinding kids through exams which don't tell us anything meaningful.
I've got another demonstration for you.
It's a better one.
This is the mystery box, please observe.
Now, when you see that, who has a question?
Who's curious about this?
Who wants to run up on the stage,
pull one of these strings, and see what will happen?
Yes, this is the reaction we want from our students!
We want them to be curious.
When I show my students the mystery box, they say, "Show us what's inside!"
But I will never do that.
Of course, it's sealed.
Just like science, the mystery box isn't about the answer,
we don't have access to some sort of universal truth.
All we have are the questions.
I tell the students they can go home and make their own mystery box,
and you can do that too.
And if your mystery box works the same as mine,
then - congratulations! - you're successful.
But I will never show you the inside of the mystery box.
That's a science demonstration, right?
But most of the science learning we need to do is a little more difficult,
so let's have one more demonstration.
I have a white plastic ball, and I have a magnet.
The white plastic ball is not attracted to the copper,
but neither is the magnet because copper is not ferromagnetic.
If we drop the two through the tube,
there's the yellow plastic ball, but where's the magnet?
There it is.
So what's going on?
As it falls, the tube is feeling a changing magnetic field.
Just like in a dynamo or in a generator,
the changing magnetic field is creating an electrical current.
Because the magnet is oriented vertically,
that magnetic current is going to be travelling in circles;
these circles are called eddy currents.
Now, just like current in a wire creates a magnetic field,
the eddy currents will also be creating a magnetic field.
The magnetic field that is being created here
will be in the opposite direction
to the magnetic field that the magnet possesses itself.
Therefore, as it falls,
the magnet is being repelled by a field it is indirectly creating.
As a result, the magnet falls more slowly.
But now, you've seen the demonstration,
you've heard an explanation,
and you've seen some pictures, so you understand, yeah?
Well, let's test your understanding.
I will take the magnet,
and we will just flip it upside down and drop it through.
Is it going to be faster, slower or the same speed?
Same speed.
So, the situation is complex. It's difficult.
Electromagnetic induction is a topic
that, when I teach it, I spend hours working with my students.
We go through deliberate exercises, we build a model, and we deploy it.
Understanding ideas in science education
takes time, takes effort, and, of course, it takes careful instruction.
The technique that I use when I'm teaching is called modeling instruction.
Modeling simulates how scientists actually acquire knowledge,
and it works really well.
I'd like to show it to you.
We start off with an experiment.
The students have to find the relationship
between two carefully constrained variables.
Next, we'll meet as a class,
and we'll combine our findings together to create a model.
But because the students have created the model themselves,
it's no longer a Newton's law of gravitation,
it's Anna's law, or Ivan's law, or Alexander's law.
They have ownership over it, it's theirs.
Next, we'll take that model, and we'll apply it to real-world tasks.
Finally, we can take the model, loosen the constraints,
and see that it doesn't work anymore.
That allows us to create a new, more general model.
So, active learning approaches like this actually work;
the research is really clear on that.
It will take time and effort for us
to retrain teachers in order to teach more effectively.
But the good part is
that it's not difficult and it's not expensive.
My favorite tool in the classroom is the smartboard.
I bring the board, and the students have to provide the smart.
When I want my students to develop skills, I get them to do something real,
that's how we keep them engaged.
So last week, my students got a water balloon,
they went to the second floor and held it out the window,
and they needed to make a prediction, when should they drop the balloon,
so that, as I'm walking underneath the window,
it hits me on the head.
Let's take a look at that.
(Video starts)
There you go... falling...
bull's eye.
(Laughter)
You can see how happy they are up there, right?
(Laughter) (Applause)
Thank you.
Let's go back to Zaya.
So, Zaya was becoming increasingly paranoid
and worried about UFOs.
So what I had her do was
I had her apply the scientific thinking that she was learning in class
to her ideas about UFOs and about conspiracy theories.
Slowly, over the course of the year, she began to walk back her ideas.
By the end of the year, she was just a normal kid again.
Science and the ways of thinking that come with it
empowered her to better understand her world.
Imagine if we could have science classes
where students learned from active, hands-on, meaningful lessons.
And imagine if we could all learn to think scientifically and critically.
But there's one piece missing, and it's a big one.
Examinations.
Here in Europe and around the world,
we're increasingly turning to high-stakes standardized exams.
Every minute students spend learning how to ask questions,
how to do experiments, how to think like a scientist,
is a minute they are not spending preparing for exams.
Any change that we make to science teaching
will need to begin with a change to science assessment.
There are alternatives to these terrible exams:
projects, open-ended tasks, group work, lab work, portfolios, virtual labs.
If you're a science educator, look these up!
They have been tested, they have been used,
they've been around for decades.
I don't know why people aren't adopting them, it's craziness!
I'm here because I want to call on science leaders,
here and around the world,
to scale back their reliance on these standardized examinations
and to investigate and seriously consider alternative forms of assessment.
But I have a message for you too, and especially to students.
Science is more, so much more, than tests.
If you can use science in your thinking,
and if you can learn to think scientifically and critically,
you will be a smarter and a richer person.
We can learn to think scientifically, we can learn to think critically,
so demand that from your schools, demand that from your education system,
and demand that from yourself.
And, most importantly,
don't let tests tell you what you do and do not care about.
Learning science is hard, but it's also really important.
I think we're doing it wrong, I think we can do it better.
And, in fact, I think we must do it better.
Thank you very much.
(Applause)