Humanising Language Teaching
Year 4; Issue 2; March 02

Deduction versus Induction in EFL Teaching

Melanie Butler, Editor EL Gazette, London UK

One of the very first things I was told on my very first training course as a language teacher was that deductive learning was bad. Not only bad, it was uncreative, old-fashioned and boring.

They were very clear what they meant by induction: getting students to work out the rules of the language for themselves by presenting them with evidence.

By deduction, they meant giving the student the rules, and then getting them to work out individual examples from the rule.

"Induction good; deduction bad" was the message. And it was not a message I questioned until I married and acquired a step-daughter with a penchant for pure mathematics. Some time later, I had a daughter of my own with the same peculiar bent. Suddenly I was surrounded by girls who not only thought deduction was fun, but who insisted on not just applying rules they had been given, but deducing complex mathematical concepts from rules they had often worked out for themselves.

For people who believe, or have been taught to believe, that deduction is the wrong way to do things, this can be not only a perplexing experience but an irritating one.

To illustrate the conflicts that arise, I have set down below my memories of one conversation between my daughter and her father which took place on one of those interminable family car journeys. As you read it do not worry too much about the mathematical concepts involved - I do not remember my daughter's arguments well and I never completely understood them. Concentrate instead, as a good humanistic teacher should, on the feelings invoked, both in the speakers and in yourself..

Daughter (aged 8 ): Dad, you know there is an infinite number of numbers....
Father (aged 51): .No dear, there can't be an infinite number of numbers.
There aren't an infinite number of things in the universe to count..
Daughter (impatiently): It doesn't matter how many things there are. If you could add all the things in the universe.....
Dad: You can't
Daughter (even more impatiently). It doesn't matter. Even if you could, once you had finished counting them you could still add one to the total, and then add another one and another one and another one for ever. The number of things isn't infinite but the number of numbers is.
Dad: I don't understand. You'd run out of time....
Daughter:(at the end of her tether) It doesn't matter, if you can really do it or not. Honestly dad, if you can't understand infinity, then you must be stupid!
(Dad sulks. Silence reigns for a few minutes).
Daughter: Mum, if there is an infinite number of numbers, then there must be an infinite number of prime numbers, mustn't there?
Mum: (aged 42) I'm not sure, darling.
Dad: Who cares?

How do you feel when you read this conversation? Do you feel in sympathy with my daughter? Do you know that there are indeed an infinite number of prime numbers? Do you feel irritated by husband's inability to see this truth? Then you are either a natural deductive learner, or you come from an educational culture which values deduction and has taught you how do it.

Do you, on the other hand, you side with my husband? Does the talk of infinity annoy you because talks of something that does not exist in the real world, for which we can never have normal evidence? Then you are either a natural inductive learner or you come from an educational culture which values inductive learning and maintains that the only way to lean anything is through experience.

Or perhaps, like me, what you feel perplexed. I found my husbands arguments compelling in that they agreed with the way I had been trained to teach. But, while I couldn't quite follow what my daughter was saying I could see that she was deducing for herself complex mathematical ideas in a way that was clearly creative.

So I decided to find out more about the theories behind induction and deduction. I began to read philosophy books, in particular I began to read Bertrand Russell.

"One of the great historic controversies in philosophy is the controversies in philosophy is the controversy between the two schools called respectively "empiricist" and "rationalist". The empiricists - who are best represented by the British philosophers, Locke, Berkeley and Hume - maintained that all knowledge is derived from experience; the rationalist - who are represented by the continental philosophers of the seventeenth century, especially Descartes and Leibnitz - maintained in addition to what we know we know about experience, there are certain 'innate ideas' and 'innate principles', which we know independently of experience."
(Bertrand Russell, The Problems of Philosophy).

What we have is a kind of theory of multiple intelligences, a theory which goes back at least as far as the enlightenment, indeed the concepts of both deduction and induction can be traced back to Ancient Greece. The Anglo-Saxon empiricists, on believed there was only one valid way to obtain knowledge, through induction. The continental rationalists believed there were two: deduction and induction.

The more I read about this great historic argument, the more it became apparent to me that that the empirical belief induction as the one true path to knowledge is a peculiarly Anglo-Saxon view of the world. My teacher trainers may have been dismissive of deduction as much because they came from an Anglo Saxon learning culture as because of any evidence that deduction is a bad way to learn.

They may also not really have grasped what the rationalists meant when they talked of induction. A quick overview of Russell's writing on the subject may help to explain, to a limited extent, what the process of deduction really entails

" The process of deduction goes from the general to the general, or from the general to the particular." For example, when my daughter deduced from one general rule, that numbers are infinite, the rule that prime numbers are also infinite she was going from the general to the general.

But where does the first rule come from? At the beginning of every deductive process, there is an induction. Our knowledge that if you add one to a number, you get another number comes from experience of adding one thing to other things. However, using deduction, rationalists believe, we can work out that numbers are infinite without having to experience an infinite number of numbers. Pure empiricists believe that we cannot know any such thing unless we have experienced it.

" The process of induction goes from the particular to the particular, or from the particular to the general." Induction can never go from the general to the particular. Once you have induced a rule, say a grammar rule like "the second person singular of the present simple takes s", when you apply it to a particular example of language, when you think " so the second person singular present simple of the verb to run is runs" you are using deduction.

Does it matter how the student gets the rule? Whether it is given to them or they experience it for themselves? This really has little to do with induction or deduction.
My daughter deduced for herself that prime numbers are infinite. I know that
E=MC2
I would never be able to induce it for myself.

Whether or not we give students rules or ask them to work them out seems to me to do with how difficult a rule is to work out -something which may vary from student to student- not whether they are induce it or deduce it. I have never deduced for myself, the rule that prime numbers are infinite. I spent 20 years trying to induce for myself when it is correct to use qui in Italian, and when it is correct to use qua. Last month, somebody told me that one is used north of Rome and the other south.

So, which is the best system for learning? The answer, of course, varies with the philosopher you read. The one who convinces me, though, is Russell who argues that it depends on the subject matter. Science, he argues in his magnum opus " the History of Western Philosophy" is almost purely inductive but " all pure maths... like logic,"is deductive.

Certainly, the empirical evidence suggests Russell is right. For the last 35 years the OECD has run tests in Maths and Science throughout the developed world. The results are striking: Catholic European countries do better in Maths, Anglo-Saxons do better in Science. In fact, the only English speaking country whose results are better in Maths than in Science is Ireland, a country where Catholic rationalism has long held sway. On the other hand England, the home of empirical philosophy, ranks around 5th in the world in Science but, in the last tests, only 24th out of 28 in maths, by far the biggest differentiation between the subjects of any of the countries involved in the survey.

But what about language learning? Unfortunately, neither Russell nor any other philosopher I have read has anything at all to say about language learning. Nor is language a subject area the OECD tests cover. Popular prejudice suggests that neither England, which is better at science, or France, which is better at maths are much good at languages. While it is true that some countries that are good at language learning, like the Netherlands, tend to score equally well in both OECD subjects, there are plenty of other explanations for their linguistic competence.

I suspect neither inductive learning nor deductive learning have much to do with language learning. After all, the OECD tests show that everywhere in the world, boys out perform girls at both Maths and Science (though girls are catching up fast in Maths). All the research I have ever seen about language learning, on the other hand, suggests that girls are better. Perhaps the girls are neither inducing knowledge, or deducing it, but doing something different altogether.

So, should we consign inductive learning to the dustbin of language learning theory where deductive learning has languished for so long?

I would argue not. Induction is a useful tool and works well with learners who know, either instinctively or through educational experience, how to use it. But deduction, too can be a useful tool for students for whom it is stupid. We should rescue it from the dustbin, dust it down and see how we can use it well in the language classroom.

Above all, what we should do as teachers, is to stop insulting deductive learners like my two daughters, by telling them that their natural way of learning is bad, uncreative old-fashioned and boring.

The truth, according to Russell, is that inductivists and deductivists live in two different mental worlds.
" According to our temperaments, we shall prefer the contemplation of the one or of the other. The one we do not prefer will probably seem to us a pale shadow of the one we prefer, and hardly worthy to be regarded in any real sense, But the truth is that both have the same claim to our impartial attention, both are real and both are important..." ( Bertrand Russell, The Problems of Philosophy.)