Knowing the word for something and having an understanding of it are not the same thing

It ain’t what we don’t know that gives us trouble, it’s what we know that ain’t so.”
Will Rogers
 A common failing in all levels of science education is mistaking having a word for a phenomenon with having an understanding of it.


To take a very simple example, if I ask any of my students why the apple falls ‘down’ from the tree they will all say ‘because of gravity’.

If I then ask them what ‘gravity’ is I get a lot of mumbled responses before they finally acknowledge that they have to idea.

I don’t either.

Neither did Newton.

Scientists still don’t.

Or I could pose the following:
My book is sitting on the table. There is a force of gravity acting on it pulling it downwards.
The fact that it doesn’t fall downwards must mean that there is another equal force acting upwards.
So, I ask, what is this force?
“That’s easy”, say the troops, “it’s the table.”

But a table isn’t a force, I reply – a table is a table.

It gets better. Let’s assume that the weight of the book is one Newton.
Whatever is acting upwards (opposing the gravitational force) must therefore also be one Newton.
Now if I put a heavier book on the table (two Newtons in weight) the table now needs to push back upwards with an equal force of two Newtons. How come the table ‘knows’ exactly the right amount of force to push up with?

It’s obviously a very clever table.

What happens if it got its sums wrong and pushed up with a force of three Newtons when it should have just pushed with two Newtons?
Hmmm . . .
In our Physics and Applied Maths classes we do lots of calculations with this upward force. And because we talk about it so much we gave it a name. It’s called a “reaction” force, signified by the letter R (because we’re nothing if not imaginative).
I use this as an opportunity to predict the future career path of the students in front of me. Engineers are perfectly happy not to know anything about the origin of this reaction force. I just need to get out out of their way while they get on with the business of using it to get the right answer.
The physicist is the guy/gal who knows there is something odd about all this and isn’t happy until they get to the bottom of it.
The dilemma I constantly struggle with is the following: how much time should I spend  trying to unravel students’ misconceptions in order to give them a deeper understanding of the basic concepts when the exam is just looking for superficial answers.

So more and more I put my emphasis on the wonder of the subject. Because that’s what drew me into it in the first place, and then gradually I sorted out some of these issues myself. But I still still struggle with most of them. But it’s a wonderful struggle.


So don’t worry if students at any age don’t have a fully-worked out understanding of what’s happening. Once they’re happy to ask questions, and the environment is there to encourage this, everything else will follow in its own good time.

At least that’s what I think.

I could well be in a minority of one . .

What do lightning conductors and Global Warming have in common?

Recently when covering Static Electricity we looked at how lightning conductors work, but we also discussed why they took so long to catch on.

Try answering the following questions without looking at the answers (I know you’re not actually going to do this, but it gives you a sense how the conversation went in class).

Me: Give me some examples of what you can NOT insure your house against.
Students: Floods, hurricanes, earthquakes

Me: What are these collectively known as?
Students: Acts of God

Me: Why are they referred to as Acts of God?
Students: Because you can’t predict when or if they’re going to happen.

Me: But why would you call those events ‘Acts of God’?
Students: Because you can’t predict when or if they’re going to happen.

Repeat three times.

Me: But why would you call those things ‘Acts of God’?
Student: Because God must have wanted those things to happen – or at least that’s what the people believed back then.

Me: Exactly. And before you all laugh at how ridiculous that sounds remember that it’s not that they were any less intelligent than we are now, it’s just that life in the 16th and 17th century was incomparably different to today. We live in a so-called age of reason. We know you can’t say ‘well that’s obviously what God wanted’ every time something bad happens. And I’m pretty sure that if our civilisation survives another century or two the people who are around then will look back at some of the rather bizarre belief systems that we subscribe to. The United States contains approximately 5% of the world’s population yet in incarcerates 25% of the world’s prison population. Enlightened?

Even Newton himself fell into this way of thinking. When he found out that the orbits of the planets didn’t quite match his mathematical equations his response was to say that God obviously needs to step in and give them a nudge every so often. It took Einstein to explain that the problem was that Newton’s equations weren’t exact enough and it needed his (Einstein’s) Theory of Relativity to sort out the anomaly.

The point is that, as with so much of the Church’s teachings, its beliefs can be traced back to either St. Augustine or St. Thomas Aquinas. In this case both believed that the air was filled with seriously questionable characters. Aquinas wrote that “Rain and winds, and whatsoever occurs by local impulse alone, can be caused by demons. It is a dogma of faith that the demons can produce winds, storms, and rain of fire from heaven.”
And so, presumably, can God.

So when Franklin suggested that his lightning rod could save  church buildings he naturally thought that this would be well received (in fact he considered it to be one of his greatest accomplishments, which is no mean feat when one considers that he was also one of the founding fathers of the United States.) It turns out that his suggestion went down like the proverbial lead balloon.

If a building struck by lightning was an Act of God, then interfering with this process was akin to thwarting God’s plan. And that, in the eyes of the Church authorities at least, couldn’t be a good thing. So they simply refused to put them in.

But there was one small problem. The church building was invariably the tallest structure in every village and town. So it was also the most likely to get hit. Now as you can imagine this confused people greatly. Not only that but the bell-ringers whose job it was to alert the townsfolk about the impending storm also tended to become the first victims of any lightning strike. In Germany alone approximately 300 bell-ringers lost their lives in the last 30 years of the 19th century.

So slowly but surely Church authorities began to relent and accept that maybe it was time to accept that there was something to be said for these so-called ‘blasphemous devices’ after all. Lucky for them it wasn’t too late.

So what’s all this got to do with Global Warming?
According to one 2006 study, 76 percent of Republican citizens profess a belief in the Second Coming (the so-called ‘Apocalypse’). They also represent one of the largest groups who oppose scientific teaching on Global Warming. They simply refuse to accept that Global Warming has the potential to change the world irrevocably. Why? Because the end of the world will come at a time of God’s choosing, not ours, so whatever mankind is doing right now, it’s certainly not going to bring about the destruction of civilisation.

These religious conservatives have become a very powerful force in American politics in recent decades (how that came to be is an equally fascinating story, but not for today).

Add to this the lobby group for oil and other fossil fuels and you have a voice that is both loud and very difficult to dislodge.

Now for fun throw in optimism bias which is evolutionary hardwired into all of us. Optimism Bias is the belief that the future will be better than the past. So for example 10% of Americans expect to live to be 100 when in fact only 0.02% are likely to live that long.We all experience optimism bias. It’s why none of us mention Global Warming when political canvassers call to our door. We all just assume that it will get sorted somehow. It may even explain why we are all so reluctant to engage with the concept of our own mortality; deep down we all think we’re going to live forever.

So you can see why Global Warming remains low on everybody’s radar.

And it will most likely remain that way – until it’s too late.

Unlike lightning conductors.

This is a link to resources I use when teaching about Global Warming and The Apocalypse in Transition Year.

2016 ISTA Annual Conference


It’s interesting to note how much the ISTA (Irish Science Teachers’ Association) annual conference has changed over the years. It has always been a place where teachers could meet and share ideas but in more recent times there has been a noticeable change in focus and it now also acts as a showcase for research into education in general and science education in particular; the entire three-day event could be classified as one long session of CPD.
This year’s conference (which will be held in the Limerick Institute of Technology) is no different and the emphasis is very much on ideas that you can bring back to the classroom.
The following are perfect examples of this:

Inquiry in the Physics Lab
Leah Wallace

Evidence in school learning
Stuart Naylor

Teaching enquiry through Mysteries Incorporated

Assessing inquiry skills in science

In my last post I noted that for me the highlight will be Professor Mazur’s lecture on ‘Educating the innovators of the 21st century’, but there’s plenty more on offer if that doesn’t grab your fancy. As a profession we are only just becoming aware of how much recent (and not so recent) advances in neuroscience can teach us about how students learn. So it’s very apt that Limerick’s own Professor William O’Connor will be delivering a talk on ‘The brain science of learning and its applications in the classroom’. Professor O’Connor has his own blog called on all things related to neuroeducation which you can either subscribe to or follow on facebook.
Everybody knows that kids love asking about space but teachers are just as prone to this as everyone else; what’s out there, how did it get there, where is it all going to finish up. Unfortunately none of these questions appear on the current Junior Cert science syllabus (or any Leaving Cert science syllabus for that matter) but the new syllabus looks much more promising, so it’s great to see that Astronomy/ Cosmology featuring strongly at this year’s conference – just look at what they’ve got lined up for us:

To catch a comet
Mark McCaughrean, Senior Science Advisor in the Directorate of Science & Robotic Exploration at the European Space Agency

Bringing the world’s biggest robotic telescope into your classroom
Liverpool Space Observatory

Inspiring the scientists and engineers of the future
Amber Gell, NASA

Primary teachers
Each year sees an increase in the number of primary teachers attending and indeed there is a special program for primary teachers.
It includes talks on the following:

  • Materials: Air & Water — Hands on science activities for the classroom
  • Inquiry Based Science Education & the Energy & Forces Strand
  • Teaching Science to Infants
  • A practical activity to demonstrate the importance of Earth Observation for the primary classroom

And of course there are always new ideas on show with the  Science-on-Stage gang so nobody will be left out.

It promises to be a wonderful weekend (the main events are on Saturday but it starts on Friday evening and finishes at 1 on Sunday afternoon).
See for all details, including a full program of events.

And a mighty thank you to all the organisers in the Limerick-Clare branch of the ISTA for volunteering to put in so much time and effort.

See you there!

Eric Mazur and Peer Instruction

Eric Mazur is the Balkanski Professor of Physics and Applied Physics at Harvard University and Area Dean of Applied Physics. An internationally recognized scientist and researcher, he leads a vigorous research program in optical physics and supervises one of the largest research groups in the Physics Department at Harvard University. Mazur founded several companies and plays an active role in industry. He is the Vice President of the Optical Society.!keynotes/c151a

Professor Mazur is also a very successful university lecturer and takes his responsibilities in this realm very seriously indeed. He is highly respected by students and peers alike  for the quality of his lectures. Over the years his students’ results remained impressive and all was rosy in the garden.

Then Mazur decided to perform a little experiment. He knew his students were doing well – he wanted to see how well. He had just read a paper which claimed that many students who do well in physics tests which were of the the ‘plug and chug’ variety struggled when there was any higher order thinking involved (‘plug and chug’ refers to the process whereby a student just needs to identify the formula which links the variables, plug the numbers into the formula and chug away on the calculator). So he started throwing in test questions that were a little off the beaten track. This was Harvard University after all; students should be well able to apply their knowledge and to solve problems that were just a little different – right?
Wrong. It turned out that the students were terrible at answering these questions. Mazur was flabbergasted. He understood fully the implication of his findings; his success as a lecturer “was a complete illusion, a house of cards.”

Mazur had just discovered what every physics teacher learns at some stage in their career (but which of us choose to ignore):

“The students did well on textbook-style problems. They had a bag of tricks, formulas to apply. But that was solving problems by rote. They floundered on the simple word problems, which demanded a real understanding of the concepts behind the formulas.”

But here’s where Mazur differs from the rest of us, although according to him this happened almost by accident. After posing a problem to his students he then asked them to discuss the question with each other.

“It was complete chaos,” says Mazur. “But within three minutes, they had figured it out. That was very surprising to me—I had just spent 10 minutes trying to explain this. But the class said, ‘OK, We’ve got it, let’s move on.’

Mazur decided to tackle the issue as though it were a science investigation and this in turn lead him to develop a method of teaching which he called Peer Instruction (coupled with Flipped Learning).

The following is a typical scenario where Peer Instruction works well:
Pose a tricky question to the class. Put four possible answers up on the screen.
Allow students sufficient time to think about it (by themselves) and get them to vote using their phones.
Each student now has to find somebody who chose a different answer and persuade him or her why one particular answer is right and the other is wrong.
Students now vote a second time.
Hopefully there will be a  much greater percentage of correct answers second time around, but at the very least there should be greater engagement with the teacher in the follow-up teacher lead discussions.
It can be as simple as that.

Some points to note about Peer Instruction:
This is a link to a very useful flowchart on how to use Peer Instruction effectively:

A slightly more detailed list of the essential features and many advantages of Peer Instruction:

You don’t need clickers but you probably need wifi. Every student has a phone and there are numerous online programs out there which can collate the information as it comes in in real time (kahoot, socrative and quizlet are some of the most popular).

Peer Instruction goes hand in hand with another of Mazur’s ideas; Flipped Learning, but each can work independently of the other. Most people are probably familiar with Flipped Learning but if you’re interested you can read more here.

Don’t expect to get it right first (or second time). It’s a learning curve. We want students to see that making mistakes is an integral part of the learning process. We need to be comfortable adopting the same philopsophy oursleves. And let students know this in advance.

Show some of the videos from this page to the students so they know where you’re coming from and why. If you can all buy into this process collectively it’s much more likely to catch on:

I like this one:

Peer Instruction may work, but not for the reason we think. In this blogpost the teacher found that very few students changed their minds as a result of the discussion, but they did become much more engaged in the rest of the lesson because they wanted see if their reasoning was correct or not.

There is some evidence that it’s not the actual Peer Instruction itself that’s resulting in better understanding – it could be that Active Learning of any description would have the same effect (link to paper). I don’t know the answer, but in one sense it doesn’t really matter. What matters is that this method has been shown to work, time and time again. So if you can add it to your armory then who wouldn’t want to know about it?

I have no doubt that Mazur wasn’t the first to use either of these two ideas, but he did formalise the process, investigate it quantitatively and has promoted it worldwide so certainly deserves any plaudits that come his way,

Neither is  Mazur the first teacher who admitted how ineffective his teaching was.
American high school physics teacher Frank Nochese coined the term ‘pseudoteaching’ for much of what we do in our science/physics classroom.
It’s a fascinating subject area in that it brings into question all that we do, but as I mentioned up top it’s too tempting to just keep on doing what we’re doing and assume that everything’s ticketyboo.
For more on pseudoteaching see here:

Both Peer Instruction and Flipped Learning can be very powerful tools when addressing misconceptions held by students. This is a major problem in science education (assuming you want students to get more from your teaching than just the ability to pass an exam).
The following is a link to many useful resources in this area (note: to deal with misconceptions effectively you must first be aware yourself of the misconceptions which students are likely to hold):

This particular post was prompted by the fact that Professor Mazur will be giving two presentations at next weekend’s ISTA annual conference.
The first is entitled: Educating the innovators of the 21st century
and the second (with his other hat on) is entitled: Wrapping light around a hair

Both will be on Saturday 09 April in the Limerick Institute of Technology.
Program and registration details are here.

Can’t wait.









When the issue isn’t ability – it’s motivation

I have read a lot of information on how to become a more effective teacher.

Much of it seems to assume that the students want to do well, but there are plenty of situations when the student or students just don’t seem to care. For starters they know there is little at stake at Junior Cert level, whatever about the Leaving Cert.

Many students would defend the fact that academia isn’t where their future lies – so where do we go with that?

And there is remarkably little in the way of helpful information here.

Most of what I have found I put here:

This also ties in the issue of discipline:

but I think Neil de Gras Tyson nailed it on the head with the following:
“We spend more time forcing students to learn than we do motivating them to learn in the first place.”

You see all that theory is well and good. But then you find yourself trying to motivate a lassie like this and quickly find that the best laid plans . . .

Why are some study-techniques effective while others are not?

When students return after the Easter break there will be a little over 30 school-days left.

You will have the distraction of the orals, plus possibly some project deadlines.

30 days is not a lot.

A quick re-cap on Study Skills is in order.

Rather than focusing on what does and does not constitute effective study, let’s look at why some techniques are effective, because once you know this you can use it to analyse your own study habits.

Your brain takes in way more information every day than it can possibly retain (what you had for lunch yesterday, what the the weather was like , who you sat beside, who walked by as you were eating, what you talked about etc.

Consequently the brain has developed (evolved) a pretty reliable rule-of-thumb for establishing what is worth keeping. If the information has never been retrieved within a suitable period of time then the brain figures it’s obviously not all that important and allows it to be ‘forgotten’.

The following is a useful analogy

Imagine that your brain and your memory are two separate departments in your head.
Every time you retrieve some information your brain automatically sends a memo to the your memory letting it know that this particular nugget of information seems to be useful and may be worth keeping, if only for a little while. Your memory department duly files this away in the bottom shelf of its long-term storage unit.

The next time it gets retrieved the brain sends another signal to the memory department, but also includes a reminder that this is now the second time that the information has been retrieved so this is definitely not some random piece of information (like what you had for lunch yesterday) and consequently it needs to be stored even more securely this time around.

So every time the information gets retrieved it results in it gets stored more securely in long term memory.

Conversely if you’re studying but using a technique that doesn‘t invoke retrieval of information from your memory, then it’s probably not effective.

And that, in a nutshell, is all you need to know in order to determine whether or not a specific study technique is likely to be effective..

So now can you see why highlighting is not particularly effective?

And reading?

And transcribing notes?

And copying mindmaps?

And making flashcards?

Can you see why testing yourself and teaching others are, by some distance, the two most effective techniques?

Can you see why reading can actually be counter-productive? Not only does it not lead to long-term retention of information, it also unfortunately creates the ‘illusion of knowledge’; you think you’re learning, and if you’re re-reading the information then you probably have a sense of having read it before, so you think you’re reinforcing the learning. But unfortunately this is not the case.

Now of course you do need to read the material to begin with, and you may want to highlight or take notes as you go along. But this is merely laying the groundwork; DO NOT confuse this with the act of storing the information in long-term memory. Ask your thespian colleagues how they learn lines for their plays. You think they go around reading, highlighting and then re-reading the information and then hope for the best, or is it more likely they read the information and then rehearse their lines every chance they get?
There’s a good reason for this. Busy actors can’t afford to spend their time on ineffective learning techniques, no matter how therapeutic they may be.
So whether you call it testing yourself, rehearsing or retrieving information, it all amounts to the same thing – effective learning.

Why are we reluctant to engage with this process?

I guess the whole concept of ‘testing’ has such negative connotations that we avoid it at all costs if we can. Confirmation bias also plays a role here; we tend to engage more with advice which we already agree with, and tend to disregard information which we don’t want to hear in the first place.

There’s also something therapeutic about highlighting; it’s akin to the pleasure you got from colouring in pictures as a kid. Re-reading can also be almost pleasurable (if it wasn’t for the knowledge that there is an impending exam at the end of term), and even writing out notes needn’t be too much of chore, particularly if you can do it while watching tv or listening to music.

But testing yourself? No two ways about it; that’s going to be a pain in the sweet derriere every single time.

Which is why it remains the only effective study-skills technique you should be practicing (unless you’re teaching others).

For more information on effective and ineffective study techniques click on my learningishard website

Guidelines on carrying out the JC Physics investigation 2016

The following is the title of the Junior Science Physics investigation for 2016:

Investigate and compare the quantitative effects of changing

(a) the pendulum length and

(b) the mass of the pendulum bob on the period (time of oscillation) of a simple pendulum oscillating through a small angle.

This investigation is a slight variation on a leaving cert physics investigation so if your teacher doesn’t teach physics then you may be at a slight disadvantage when it comes to understanding some of the nuances of the experiment.
This is my attempt to level the playing pitch.

Just understanding what you’re being asked to do is tricky, so let’s simplify it a little.

  • The words investigate and compare mean pretty much the same thing in this context. So for now let’s just use investigate. But we will come back to significance of the word ‘compare’ again at the end.
  • The word quantitative is just telling us that we will need numbers for our results. So if we just remember that then we don’t need to refer to it again.
  • The term simple pendulum refers to a pendulum that consists of a single string with a mass at the end.
  • The word mass is similar to the word weight. In your notes on Forces in Junior Cert Physics we explain what’s different about them, but if you’re just trying to get your head around this investigation you could consider them to mean much the same thing for now.
  • The pendulum consists of a piece of string and a metal ball (the technical term is a plumb bob) so if you want to change the mass of the pendulum then you need to need to use a heavier or a lighter ball.
  • The period (time of oscillation) refers to the time for one complete swing; all the way over and all the way back to the starting point.
  • The phrase oscillating through a small angle means that when we pull the pendulum back, we shouldn’t pull it back too far before we release it. What does ‘too far’ mean? Well you could pull it back until the string is horizontal, and that would definitely be too far. So try for not more than about 45 degrees.
  • The term period (time of oscillation) means the time it takes the ball to go through one full cycle. So you would start your clock when you release the ball, and then stop the clock when the ball gets back to the starting point.
  • There’s a part (a) and a part (b), and by putting both parts in one big long sentence it only serves to confuse what we’re being asked to do. So whoever put this together didn’t do a particularly good job.

Let’s re-write it as follows:

(a) How does changing the length of a pendulum affect the time it takes the pendulum to do one full swing?

(b) How does changing the weight of the pendulum affect the time it takes the pendulum to do one full swing?

Now let’s come back to this word ‘compare’ again. What it means is, “Does increasing the  length of the pendulum have the same effect as increasing the mass (on the time it takes the pendulum to do one complete swing)”?

When looking at how the time for one oscillation varies with mass, the variables are obviously mass and time. So the length needs to be kept constant. This can be trickier than it might appear.
Is the string oscillating about a fixed point? Look closely at top of the string to check. If it’s not then the length isn’t constant. What could you do to try and keep the top of the string fixed?

Where do you measure the length of the pendulum from?
Answer: From the top of the string to the center of mass of the ball.
At junior cert level you could probably just estimate where the center of the ball is, but at leaving cert level you should be more precise – can you think of how you would do this? If so then include it in your comments at the end of the booklet.
But what if the heavier ball is also larger than the old ball – will this change the overall length of the pendulum?
How could we use a larger ball and still keep the overall length constant?

Guess what will happen before you carry out the investigation. You can then refer back to this at the end in the comment section. Did you guess correctly or were you surprised by what you found out? It turns out that a lot of science is what we call counter-intuitive; this just means that a lot of the time what we find isn’t what we thought we’d find (‘against common-sense’). Which is why we always need to test our predictions. After all, it’s not exactly obvious that the earth is round, or that humans evolved from just a bunch of chemicals now is it?

So what do you think will happen to the time for one full swing if you use a longer string?
What do you think will happen to the time for one full swing if you use a heavier ball?

In the Electricity chapter in Junior cert physics there is an experiment where you investigate the relationship between current and voltage (potential difference) for a metallic conductor. When you plotted a graph with current on one axis and volts on the other you (should have) got a straight line through the origin.
A common exam question asks you what is the relationship between current and voltage, and how do you know?
The answer is that ‘they are proportional’ – we know this because we get a straight line through the origin.

In our experiment to investigate how the time taken for one swing varies with the length, do we get a straight line through the origin?
If the answer is yes, what does this mean?
If the answer is no, what does it mean?

It turns out that investigating the motion of  a pendulum was one of the first and most important experiments in all of Science. To see why (and to get some hints on how to carry out your investigation) look at the video here.
And good luck with it

It’s a nice investigation; pity all the good is taken out of it by how it’s assessed: