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March 21, 2006
The 'I lied' method of explaining technical concepts
One of the most effective ways of explaining a complex technical issue to somebody is to use the 'I lied' (IL) method.
We have all encountered the IL method in one form or another during our formal education. It's basic form is simple and here's how you do it:
- Initially, present a simplified version of the concept, glossing over any intricate concepts and (especially) implementation details. Lie by omission or commission, either by not revealing the whole truth or by stating the opposite of a key technical point.
- Say 'Wait a minute. I lied' and explain what the lie was and how to convert it to the truth. In doing so, construct a more technically sophisticated explanation of the concept.
- Rinse. Repeat.
The constantly changing set of assumptions underlying the concept at hand leaves students intrigued and eager to learn more about it, which can never be a bad thing. More importantly though, this pedagogical technique takes advantage of the way in which our brains are wired--to notice change. Given a changing scene with a uniform background, our perceptual system is wired to tune out the background once it has been processed initially. Subsequently, the perceptual system notices only incremental changes in the scene--be they visual, auditory or otherwise--and deems them the foreground. The foreground tends to contain the interesting things in our environment--food, a potential mate or a distress call.
The above line of thinking can be extended to the conceptual realm as well. With the IL technique, a teacher starts out by building a simple, but complete, mental model of a concept--one that has a small set of axioms. In successive iterations, certain axioms are negated and replaced, perhaps repeatedly, either by more sophisticated ones or by different ones entirely. If these axioms are central to understanding the concept, our perceptual system will track them across changes and deem them as the 'foreground', i.e. important to understanding the concept. If you're wondering why the perceptual system works this way, you are not alone. One of the fundamental problems AI researchers grapple with today is figuring out how our perceptual system picks out the salient elements in a scene. For example, given the sentence "His Acura skidded through curtains of rainwater and passed by a dog trying to shelter itself by a fire hydrant", why do we pick out that the skid has something to do with the rain rather than with the dog?
When applying this pedagogical technique effectively, a teacher will choose to negate and replace the foreground axioms essential to understanding a technical concept. When this technique is done right, students can gain a powerful grasp of the essentials of any technical concept. Of course, the teacher too must learn to identify which are the foreground axioms essential to understanding a concept, something that gets better with practice. A good teacher ought to be able to figure them out--some say that is indeed the essence of intelligence.
Posted by Vishy at March 21, 2006 04:19 PM