Irreducible complexity

The summer before I started university, I was given a reading list. On this list was Richard Dawkins’ “The Blind Watchmaker”. It had a major impact on me. Prior to this point, I had implicitly accepted a concept known as ‘irreducible complexity’ which can be encapsulated by the question: What use is half an eye? Basically, proponents of irreducible complexity doubt whether something as complex as an eye could evolve through a series of infinitesimal steps, each of which confers a small but significant advantage on an organism in the way that Darwinian evolution suggests. Instead, these features must emerge fully-formed. In The Blind Watchmaker, Dawkin’s patiently describes each tiny step in the evolution of the eye; how a patch of light-sensitive cells confers an advantage over organisms which cannot sense light, how having these cells in a depression on the skin gives some sense of the direction of the light and how this is an advantage over just having the cells on the surface and so on. Dawkin’s proceeds to build to a whole eye in such steps. He even notes that eyes have evolved independently in a range of different organisms.

Matticus78 at the English language Wikipedia [GFDL ( or CC-BY-SA-3.0 (], via Wikimedia Commons
Matticus78 at the English language Wikipedia [GFDL ( or CC-BY-SA-3.0 (, via Wikimedia Commons
Most of those who accept irreducible complexity are motivated by religion. It is a key argument put forward for pseudoscientific theories of intelligent design which reject evolution in favour of some form of creator. I had a more idiosyncratic view, holding that evolution did occur but must have proceeded via great bursts of mutations, probably caused by radiation from space. Whatever I had thought, Dawkins changed my mind.

However, I think that we can draws some useful parallels here for education. Consider an intervention, teaching method or innovative approach. Must it be adopted wholesale? Will implementing parts of it give some of the claimed advantages? Of course, it is entirely possible that there are interventions that are greater than the sum of their parts but if this is the case;

1. Why is this so? What mechanism causes it to work only if all components are present?

2. Is it really going to be possible to implement this intervention at scale if it’s only going to work if everyone adopts it faithfully?

The problem with accepting the irreducible complexity of a particular approach is that when and if it fails to produce results then proponents of the intervention can always claim that it wasn’t done properly. This can even approach the ‘no true Scotsman’ fallacy whereby the fact that it didn’t work proves it wasn’t implemented properly. In scientific terms, we have an unfalsifiable claim.

How can we be sure something is not irreducibly complex? If we examine Engelmann’s Direct Instruction then the different components of it should each confer some advantage over not having them in place; explicit instruction on concepts and procedures, immediate corrective feedback, practice, a systematic approach (over a serendipitous one) and scripted lessons. I think the evidence supports the first four of these, with some caveats around how and when feedback should be immediate. I am not so sure about the scripting of lessons because I know of few other examples where this is used. On balance, I am happy to conclude that such an approach does not display irreducible complexity and is therefore likely to work at scale.

Try applying this test to a different intervention.


Meat and Potatoes

The old manufacturing city was struggling. The government had long ago decided that service industries were the future and that banks were the greatest of these. The bankers had decided that the factories should be sold, stripped and sent overseas.

So the city decided to reinvent itself. It had a reputation as the home of meat and potatoes. Perhaps this could be a thing? Maybe they could reinvent themselves as a restaurant destination? The council decided to run a competition. Which restaurant serves the best meat and potatoes in the city?

Abitur was a small restaurant in one of the side-streets far from the city-centre. It had a fine history but had gone through a stage of being somewhat down-at-heel. That is until a brilliant and strict head chef took over. He whipped the place into shape, specifying ingredients and methods, rigorously surveying amounts. By the time of the competition this old head chef had retired, but he had left Abitur as a highly effective operation.

In fact, Abitur was so effective that it won. Crowds flocked to eat there. Restaurateurs and critics beat at the door. The new head chef conducted tours. “This is our new venture,” he said. “We are giving our chefs creative expression; using a range of meats; new varieties of fancy potatoes.” Words like ‘jus’ and ‘marrow-bone reduction’ could be heard.

All the other restaurants started copying Abitur.

But something strange was happening. Critics started to notice a decline in the quality of Abitur’s signature dish. Instead of a focus on meat and potatoes, the new head chef wanted to invite diners to wear a set of headphones playing the sound of seagulls pooing on a cliff whilst sitting inside a large papier-mache aubergine, chewing on a salty piece of dried bread.

“It is phenomenon-based gastronomy,” the chef exclaimed. “We are doing away with all of the old divisions of dishes and courses and things like that.”

People started to complain. They complained about the prices, about the service and, most of all, about the meat and potatoes.

“Why do you judge us purely on meat and potatoes?” Cried the chef, “Restaurants are about so much more than that! You are defining a successful restaurant too narrowly.”

Further Reading

Do you want a learning revolution?

It may seem strange, but if you want a learning revolution then the first thing to consider is the removal of classroom walls.

I have been involved in this innovation twice now.

The first time, I was a student at a school in the English Midlands. My school innovatively created an open-plan technology department. I thought it was great. During GCSE technology lessons I would sit and talk to Angela about The Swamp Donkeys, Fretblanket or a coming Friday night excursion to Wordsley. When challenged by a teacher to actually do something, we would make the right noises before moving to one of the other ‘rooms’ to continue our conversation.

One of my friends used to duck out of the fire escape in order to… erm… take the air. For most of every lesson. The teachers didn’t seem to like the arrangement because they never knew where we all were.

I didn’t do very well in GCSE technology. I can’t be sure but I think the school eventually put in partition walls.

About ten years later I was working as the Head of Science in a school in West London that was totally rebuilt under the Private Finance Initiative. The architects did some strange things like placing light switches in the corridors. We tried to tell them not to but we weren’t allowed to comment on details like that. Instead, we had to feed our thoughts into a ‘specification’ for what the building was mean to do rather than exactly what features it should have.

So we were given an open-plan Art department. The teachers didn’t like it very much because it was quite noisy and distracting.

We ended up ordering some partition walls.

And so I read with interest about a school building in Sussex that was unveiled in 2010 with open-plan pods catering for 90 students at a time. Apparently, the idea was to transform the learning agenda. However, according to a newspaper report, the layout was not necessarily popular with parents or conducive to high standards. The new principal wants a complete refurbishment.

In the meantime, they’ve put up some partition walls.

Education is upside down – A Review

As a proponent of explicit instruction, character education potentially causes something of a problem. I certainly don’t think that you can stand at the front of a classroom and instruct students in developing their characters or personalities. Instead, I think that this occurs implicitly. I am not sure how much a person’s character can be shaped but insofar as it can be, this is through experience.

This apparent contradiction may be understood by an appeal to evolution. Personalities have been around for millions of years and have therefore been subject to evolutionary pressures. So we develop them in the same way that we develop walking or talking; experientially. However, the objects of school instruction such as reading and mathematics are recent inventions and thus need to be transmitted by more explicit means. This line of thinking has left me wondering what, if anything, a school’s role is in character education. Is it about playing winter sports on a muddy field or participating in community service? Does it occupy the fringe of school life?

Eric Kalenze has given me a new perspective on this problem after reading his excellent book, “Education is Upside-Down: Reframing Reform to Focus on the Right Problems.”


Throughout the book, Kalenze uses the metaphor of a funnel. He claims that the funnel of education is upside down. Instead of education fitting students for the world that they are to inhabit we attempt to fit the world to our students. He traces this back to the progressive movement in American education at the start of the 20th Century.

Kalenze sees the role of school as being to prepare diverse students for participation in institutions such as college, careers and civil society. It is as if we want to pour a liquid into a vessel with the aid of a funnel. However, because this funnel is upside-down, much of the liquid just bounces off the sides and never makes it into the vessel. Only that proportion that was already on the right path will pass through the narrow opening. Likewise, only students from families with an academic tradition will be inducted into academic ways at home and so make it to College.

Much of Kalenze’s argument is focused squarely on American public education. He notes that reformers simply don’t see the problem. Although desperate to improve schools, they take the same ill-conceived approaches of personalisation and engagement that the system already prioritises; cue one-to-one iPad policies and the rest. Instead of solving the real problem, these reformers seek to measure, reward and punish. They measure flow in and out of the funnel. They provide money linked to performance, they report, they close schools. But the funnel remains upside-down no matter how much they shout at it.

Interestingly, Kalenze points to a lack of high stakes assessment as a problem in American education. “What?!” I hear you exclaim in disbelief. The problem is that assessment in the US is high stakes for the schools and teachers but not for the students. Apparently, there are no compulsory leaving exams at the end of a US High School career. Kalenze contrasts this with supposedly progressive Finland where the final “abitur” exam is demanding, rigorous and high stakes for the students involved.

Kalenze draws the reformers’ comparison of choice by relating education to a business. Imagine a gym. If you buy a gym membership and then never go to the gym then that is your loss. You can’t complain to the gym owner if you don’t lose weight. However, schools are judged on the performance of everyone with a membership, whether they turn up to the gym or not. This is a problem because the customer is the product. Clearly, it is tasteless to think of students in these terms but if you are going to apply a business model then it needs to fit. And such a business model just doesn’t fit schools.

Which brings us back to character. Kalenze does what I never thought to do and asks: what character? We can develop all sorts of character traits so which ones do we want to develop in school? Well, if we want to fit our students for the institutions of college, careers and civil society then the character traits that we need to develop are those that come from grappling with difficult and not-always-immediately-rewarding work. In other words, we will develop such traits by ensuring that students apply themselves to school work.

After all, that is what school is for.

Eric Kalenze was kind enough to send me a review copy of his book.

Stand-out teaching – minus differentiation

Every pupil is unique, but does meeting their needs have to mean creating countless variations of a lesson? The evidence says no

Ever since I started teaching I have felt guilty about differentiation. I can’t remember much about behaviour management from my training, but I do remember that differentiated teaching strategies came up a lot. Since then, I have periodically marvelled at those super teachers who seem to have it sorted.

Continues here on the TES website

Carts and horses

I have been worrying recently about engagement. A few things have come together. Firstly, David Didau wrote an excellent post on the topic that made me think. Then, following my piece on explicit instruction in The Conversation, a Sydney radio show broadcast a report on inquiry learning. In this report, inquiry learning was promoted by its ed school advocates as raising student engagement, particularly in science subjects. I have also been reading an excellent book by Eric Kalenze that attempts to diagnose the problems in American public education. Eric uses the metaphor of a funnel that is upside down. I am going to talk about carts and horses.

The logic that I wish to refute is as follows:

1. Inquiry approaches are more engaging than explicit instruction

2. Greater engagement leads to greater learning

3. Therefore, inquiry approaches lead to greater learning

I think this is the logic behind the comments in the radio report.

Firstly, the notion of engagement is problematic. What we actually mean is that students are thinking about something and find this motivating. However, thinking is impossible to observe and so we have to define it in terms of behaviours. This is a difficulty because you can be thinking and feeling motivated without actually doing anything at all. If we define engagement in terms of behavioural activity then those teaching approaches that involve more student activity will be more engaging by definition.

To see this in action, it is worth examining a study of ‘curiosity’; something often seen as concomitant with engagement. In this study, researchers presented children with a new toy in different ways. In the first condition, the researchers demonstrated how the toy functioned. However, they did not demonstrate all of the functions of the toy and yet they did not make this clear. In the second condition, the researchers pretended that they didn’t know what the toy did and demonstrated the same function as if they had stumbled upon it by accident. After both conditions, the children then played with the toy. Children in the second condition spent more time looking for other functions of the toy and were thus deemed more ‘curious’. The conclusion was that explicit instruction, which the researchers thought was represented by the first condition, was less effective at inducing curiosity than inquiry, which the researchers thought was represented by the second condition.

Firstly, the children’s behaviour is quite rational. In the first condition, they assume that they have been given complete information whereas in the second condition they do not. Furthermore, both conditions start with a demonstration of the toy which is pretty explicit. The difference is in how this is done. However, note the problem. Curiosity is defined as a behaviour; specifically, it is defined as participation in discovery learning. Therefore, by definition promoting discovery learning will promote curiosity as one is defined in terms of the other. You may think this is reasonable but what of the student who is inspired to curiosity by an interesting lecture or story? Is this not possible? Is it only truly curiosity if the student then goes on to do something?

Now let’s examine propositions 1 and 2. I think that there is an arts view of science from which we science teachers suffer. Those who never found science to be very interesting at school assume that this must be because of some fault that lies outside of themselves. Science is boring and so it needs to be taught differently. Real scientists don’t sit at desks; they do experiments. And so this is the answer.

Firstly, this will not necessarily be motivating for students. I am sure that most students will agree with a proposition to do more experiments but will they really enjoy filtering sandy water or melting ice more than a discussion about the dinosaurs, aliens or how to make explosives? It’s not a sure thing.

So to proposition 2: Does greater ‘engagement’ in inquiry lead to better learning? This confuses learning science (pedagogy) with doing science (epistemology). The two are not the same. Science is done by experts with lots of background knowledge, usually acquired through pretty traditional means. Students learning science in school are novices. We can examine the scientific method in order to highlight the difference between novices and experts.

When a professional scientist sets up an investigation, she will have a lot of knowledge about what she might be looking for; enough to develop and test a sophisticated hypothesis. She will know pretty much everything about the situation apart from the one thing that she wants to find out. And she might already have a good idea about what this will be.

A student conducting an investigation into something about which they know very little will struggle to form a good hypothesis. They will have little background knowledge – even if they’ve done a bit of research on the internet – and they will also have to deal with the novelty of all of the technical aspects of conducting the investigation. Taken together, this is unlikely to lead to the learning of any new science.

For example, I remember completing a self-directed investigation as part of my physics A Level. I enjoyed this a lot and I do think that such investigations have a limited role to play in science education. I took two solenoids and placed them side-by-side. I passed an alternating current through the first which induced an alternating current in the second. I then place various barriers in between them to see which ones reduced the current in the second solenoid by the most. I did not learn any physics from the process. I took physics knowledge into the inquiry; the same physics knowledge that I left with. I found aluminium to be the best shield (compared to paper and lead) and yet I couldn’t explain why.

More significantly, relying on engagement to deliver learning places the cart before the horse. As an experienced teacher, I can engage any class in activity quite easily but this will not necessarily lead to learning. Just utter the phrase, “Today we are going to make a poster about…’ and the majority of high school students will happily spend an hour engaged in bubble-writing and the rest. But unless they learn something then this is all pretty pointless. Isn’t it?

Placed the other way around, we can see the proper role of motivation. People tend to find getting better at something to be motivating. What is the difference between motivated high school science students and unmotivated ones? I suspect a key difference will be how much science they know. It is our role as teachers to set high expectations and hold students to those expectations. As their learning progresses and they start to feel more expert, confidence, enjoyment and motivation may come. The subject may even turn in to a lifelong passion. Of course, it also may not. But at least our young charges would have learnt some science.