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:
- The nearest star is called ____________ _____________
- The distance to the moon is about 10 / 30 / 100/ 3000 times the Earth’s diameter.
- 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.