Too Much Teaching is Wasted


Let me give you some information: (Try to imagine that you’re going to learn it.)

  • The Earth-Sun distance is used as unit of distance called the Astronomical Unit. 1 AU. 
  • The Earth-Moon distance is 0.0026 AU to 2 significant figures. 
  • The nearest Star is Proxima Centauri (part of the Alpha Centauri system. Pronounced ‘Sen-TOR-eye’). The distance to Proxima Centauri is 270,000 AU to 2 significant figures. 
  • On a scale we can relate to, let’s say 1 AU is 1 metre. The length of a metre ruler. 
  • This makes the Earth-Moon distance 2.6 mm; the Earth-Sun distance, 1 metre, and Proxima Centauri 270km – on our scale model. 
  • In fact the Moon is 384,400km away.  This is about 30 times the diameter of the Earth. 
  • The International Space Station orbits 400km above the Earth which has a radius of 6371km. The moon is about 1000 times further away than the ISS. 

It’s quite easy to imagine the gap-fill worksheet in a typical classroom:

  1. The nearest star is called  ____________  _____________  
  2. The distance to the moon is  about 10 / 30 / 100/ 3000 times the Earth’s diameter. 
  3. If the Sun is 1 metre away in a scale model, the distance to the moon is 0.26mm / 2.6 mm/ 2.6 cm/ 26cm. 

Students who complete this worksheet during the lesson minutes after being taught about the information will happily fill in their sheet, answer a few questions, stick the sheet in their books and skip off to break.   They may never encounter this information ever again. Even if they were asked to pronounce Proxima Centauri in class, they may never say the words again.  They may never be asked to recall the distances, in absolute or relative terms ever again.  What have they learned? … What will they remember in an hour, a week, a month, a year?

I’d say that this type of super-short-term ‘learning’ is all too common.  The teaching has been wasted because there is not remotely enough emphasis on the process of securing the information in long term memory  or on practising the mathematical skills involved.  The topic has been ‘covered’. But what does that mean exactly?  Students will later say – ‘yeah, we’ve done scale models; we did that Earth-moon model thing’. They’ll be familiar with it – but will they have learned it?

Of course, some lucky ones will and some won’t.  But – lets’s assume we want all students to retain this information so that they have a good understanding of the relative scale of various distances in the cosmos.  It’s not merely a case of knowing the numbers as bits of google-able pub quiz info; it’s about them having a really secure understanding of relative distances to inform their mental picture of scale in the universe.  Let’s just assume we actually care that all our students remember the things we teach them.

To begin with, we might tell the class that this information isn’t just some  information.  It is the information. We could present it as a neat knowledge organiser so that students can see exactly what they need to know.  As we teach it, they could be engaging with the information knowing that, in 20 minutes and then again next week, they’ll have a multiple choice test on it. This could be repeated a few times in the coming weeks.   Similarly we could practise the mathematics involved in making scale models with various different cosmic objects – the planets for example.  We could practise saying the names of stars out loud and make sure, by checking, that every student can do it properly.

Basically, if we’re teaching it with the explicit goal that the students must remember it later – at various spaced points in time – then it informs how we give the information and what we expect students to do with it.  It’s just no good exposing students to information hoping it sinks in somehow after a few immediate recall exercise.  This is what I call wasted teaching.  It’s inefficient and ineffective.  But it happens a lot. Rote learning has a bad name.  Call it what you like, do it how you like – but teaching students so that they can actually remember things is our job; that IS teaching.

And don’t kid yourself if you think ‘you teach for understanding not just to regurgitate in a test’… Zzzzzz.  (In other words, you can’t teach for understanding and somehow bypass the process of teaching for recall if you want that understanding to last for any length of time; it’s not something you can do instead.)

How are you doing yourself?  Remembered the info above yet? Do you understand the real relative scales involved?  Test next Tuesday.  Be ready.


  1. […] Let me give you some information: (Try to imagine that you’re going to learn it.) The Earth-Sun distance is used as unit of distance called the Astronomical Unit. 1 AU.  The Earth-Moon distance is 0.0026 AU to 2 significant figures.  The nearest Star is Proxima Centauri (part of the Alpha Centauri system. Pronounced ‘Sen-TOR-eye’). The … Continue reading → […]


  2. Spot on Tom! It also sounds like a lot of teacher CPD … how bad is some of that? E.g. … We gave you Behaviour Management training, so how come you are still having problems? (Because that half a day’s training was never part of a coherent long term plan)


  3. “‘And don’t kid yourself if you think ‘you teach for understanding not just to regurgitate in a test’… Zzzzzz”

    Hi Tom

    I would like to say first that I am glad I read this post although I am a little sad that you come across here as being self absorbed and sometimes a little insulting. This for me is a departure from your previous stuff.

    You are of course quite welcome to your view on anything, and you are welcome to go to sleep when I suggest I teach for understanding and not just to regurgitate in a test, but I can assure you that it is exactly what I do and I don’t believe I am wasting my time.

    I like Marzano’s dimensions of learning and for me the model works as a solid base for teaching, which after all is a complex concept that may be described and understood in a good many ways, all of which are no more or less correct than any other. Some people talk of motivation, others of Direct Instruction while yet others talk of group work. Then there is the issue of tacit vs explicit knowledge, procedural vs semantic vs episodic knowledge, short and long term memory and the cognitive load stuff that might be drawn in. I am quoting these just to illustrate my view that there are many ways to thing about learning and therefore teaching.

    I like to combine types of knowledge with cognitive processes as a two dimensional thing, other I know do not.

    And I really do believe that I do not teach just so that students can regurgitate knowledge in a test. They are able to regurgitate knowledge in a test and this for me is part of the job. I really do want students to be able to analyse a situation based upon explicit knowledge and at the same time dredge up some tacit knowledge or a gem that they could not regurgitate in the test but have recalled/recognised and drawn into the mix for consideration.

    I don’t suggest that others who do teach “just” to regurgitate in a test are doing wrong, this might be the way that they plan their delivery etc. I know of very few people who would describe what they do in this fashion.

    I read widely, experiment daily and am refining my practice. Teaching to the test is only ever an issue for me if one restricts ones teaching to the narrow considerations of the test. I read Deans for Impact and many other useful summaries of what is useful and what is not.

    There are a group of people I find who feel that they and only they have found the holy grail of good teaching. Sometimes it seems that almost everyone blogging about education these days considers themselves to be the expert and when a small group form up into a self congratulatory mutual appreciation society taking the high ground I believe the discussion takes a turn for the worse.

    Most people I know are teaching “short term” because of the amount of material they are required to get through and in the end the student may achieve a better GCSE or A Level grade as the student will have covered more ground. Many teachers I speak to know they do this are sad as a result.

    This quote, “‘And don’t kid yourself if you think ‘you teach for understanding not just to regurgitate in a test’… Zzzzzz” for me does you a disservice and dismisses the many years skill, experience and training of those who might see the same “teaching and learning” from a different perspective than you do.

    Sorry for the rant, but I was quite disappointed. If I have completely misunderstood then my apologies.

    Liked by 1 person

    • Quite a rant but that’s fine with me. My point in that quote is that too many people are actually reluctant to teach explicitly so that students remember what they’ve been taught. There is no ‘just to regurgitate’; if students have retained information enough to retrieve it later, that’s a good thing. Their understanding is built on retained knowledge not instead of having that knowledge. I see this too often – a lesson where I think: these kids have no chance of remembering this because they’re not being expected to. All kinds of interesting ideas, words, explanations tossed into the ether never to be encountered again; never committed to memory – hence the teaching wasted. It’s a real problem I think – worth addressing.

      Liked by 1 person

  4. You really nail it on the head with this one. I’m just a trainee language teacher but have been observing my mentor’s classes where she plays games with students on words that they might encounter only once or twice in a class and then not see them again for a long time afterwards. I’ve come to see that this is futile as most of the words don’t stick when you don’t see them regularly. So I’ve recently started to present my language classes with knowledge organisers of phrases I will test them on later, and it’s produced much better results.

    Liked by 1 person

    • I remember, as a trainee, thinking that various mentors had flawed methods. Be very careful about passing judgement on an experienced colleague’s methods – even if you believe you have found a better way. It’s great that you are finding the methods that work for you, and that you want to share it but, by positioning this as ‘better’ than your mentor you feed a culture that is harming teaching.


      • Yes, I agree that’s a danger. But don’t worry, I haven’t been trumpeting my own horn aloud in the staffroom. I’ve been keeping my traditional views to myself, mainly grinning and bearing my mentor’s criticism of my approach. But it can be very frustrating as a trainee teacher to be lectured by someone who still refers to Bloom’s Taxonomy…

        Liked by 1 person

  5. I think this might be one of your weaker posts. The premise is bunk – the bits of loosely associated knowledge you present don’t seem typical of lesson content/objectives. The supposed rehearsal exercise is also quite unlikely (except, possibly, if set as cover). Finally, the knowledge is likely to be revisited in subsequent lessons and the chances that someone is teaching a series of lessons without a terminal assessment of the topic/unit/module is unlikely.

    Teaching for understanding might mean developing a firm understanding of why there are different units for different distances we are interested in. This would start by introducing the distances using a common, familiar, unit (i.e. km) but we don’t need pupils to remember the distances as stated using inappropriate units. As a knowledge outcome I’d be happy if pupils knew the definition of AU and Light Year and a couple of examples of things we would use those units for. Or maybe I’ve misunderstood and your lesson is on astronomical bodies. In this case I would have a much narrower focus (e.g. things that go around the Earth)


    • Is it bunk? I’ve seen it; experienced it. Rich discussions of material with weak or even zero expectation around long term retention. Of course some specifics might not be required knowledge- just background- but my list is meant as an imagined set of required knowledge. Encountering it isn’t enough to constitute learning it. That’s the point. Lots of content in lessons is ephemeral; soon lost, forgotten. Explicit teaching and assessment with retrieval practice built-in helps a lot.


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