By Gordon Rugg & Sue Gerrard
There’s a lot of debate in education about “teaching the facts”.
There’s also a lot of debate about the definition of “facts” and about the nature of teaching.
However, a couple of things tend to be conspicuous by their absence in these debates.
- There’s a significant absence of numbers relating to facts, such as how many facts a student should know about a particular topic.
- There’s also a significant absence of categorisation systems that use more than three categories.
These absences are usually indications that a debate is focused on questions that aren’t going to produce useful answers.
So what happens when you plug in some numbers, and some richer categorisation?
In brief, you get this:
- students need to learn between one thousand and ten thousand facts
- there’s an upper limit of learning of about ten facts per hour, and
- you need to distinguish between about ten to twenty different types of “fact”.
These results have far reaching implications for education. They’re the topic of this article.
How many facts?
There’s been quite a lot of research into expertise over the last few decades, and that research has produced a range of solid and consistent findings. One of the most surprising to anyone new to this literature is the sheer volume of information that experts know compared to novices. Experts aren’t experts because they’re more intelligent or more logical; they’re experts because they know huge amounts.
One of the first researchers to investigate this area was de Groot. He and his co-researchers studied chess experts, where the chess ranking system made it easy to define experts using an objective criterion. It turned out that chess masters knew huge numbers of arrangements of chess pieces – typically tens of thousands – and could then use this knowledge to identify the best option to use at a particular point in a game.
The subsequent expertise literature has found much the same across a range of areas. Usually the experts know tens of thousands of pieces of information about their field, and usually it takes about ten thousand hours of learning to become an expert.
This finding needs to be treated with appropriate caution. It isn’t simply the case that studying for ten thousand hours will automatically make you an expert. The reality is more complicated. There are particular things that you need to do and learn to become an expert in a given field, and those things typically take you about ten thousand hours. If you don’t do and learn the right things, then you probably won’t become an expert, no matter how long you study.
There’s also the question of what constitutes “an expert”. In some fields, there are objective criteria, as in chess, where an expert can beat a novice clearly and consistently, or where an expert can do something that non-experts are unable to do, such as particular manoeuvres when flying an aircraft. In other fields, expertise is much more subjective, and is more a matter of acclaim by already acknowledged experts in the same field. That’s a big, interesting topic about which we’ll blog again in the future.
How many facts per hour?
The sheer volume of information needed to become an expert is surprising to most people. Another surprise comes if you do the basic calculations for how quickly someone can learn that information. If you take a figure of ten thousand hours to learn several tens of thousands of pieces of information, it means that the trainee expert is learning just a few pieces of information per hour.
That’s not so surprising if you bear in mind the neurophysiology of learning. New synapses formed by the learning process take time to grow – hours rather than minutes. So there’s a hard limit on the amount that a student can learn and retain in a given session.
Big facts and small facts
One important issue is the nature of a “piece of information”.
The expertise literature clearly identified the significance of what is known as “chunking”. An expert is typically able to combine several pieces of information into a bigger unit, known as a “chunk”. An example in chess would be a particular defensive configuration of a king and three pawns. The expert can then mentally treat that chunk as just one piece of information, thereby reducing the load on working memory.
This becomes particularly significant when a student is learning how the different parts of a topic fit together. For example, Gordon’s students learn various techniques for finding out and clarifying a client’s software requirements. In a different part of the course, they are told that the same techniques can also be used for software evaluation. That piece of information is just one statement – “you can use the same techniques for evaluation that you already know how to use for requirements gathering” – but it has far-reaching implications, since it lets the students see a fresh set of connections between pieces of information that they already know.
This raises obvious questions about whether different education methods are needed for handling different types of information and different levels of chunking. In brief, different methods are needed; that will be the topic of one of our later articles.
There’s more about the theory behind this article in Gordon’s latest book:
Blind Spot, by Gordon Rugg with Joseph D’Agnese
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