17 January 2012

The Learning Curve

This article was first published on 15 January 2005.

The Learning Curve


I’ve read a fair bit lately about the learning curve and how it pertains to software. However, there appears to be a common misconception that a if something has a steep learning curve, it is harder to learn than if it had a shallow learning curve. While common, this is a misconception. With the help of a couple of graphs to illustrate what I mean, we can see that a steep learning curve means easy to learn.

First of all, what is a learning curve? Some might consider it to be a buzz-word used by marketing and personnel types to describe a hard task (which I guess it is), but it is also a very useful way of looking at several things concerned with education.

Firstly, a learning curve should (if the research behind it was good) show how much time is required to learn a particular amount (or how much is learned in a given time).

Secondly, it illustrates the law of diminishing returns nicely.

Let’s take a simple graph (figure 1). On the x axis is time [t] (as it commonly is), and the y axis will represent learning [l]. A lower value here means that less is learned than a higher value.

So let’s plot a learning curve. This is a steep one (I’ll put a shallow curve on it for comparison a bit later), and we’ll say it represents how much a person learns for a particular topic (let’s say Mathematics). After 2 units of time, a hypothetical learner would have learned slightly less than 1.5 units of learning (whatever that is!). After 8 units of time, the learner would have got themselves 3.6 units of learning.


But let’s look at a more complicated curve. This next graph shows the same curve as before, but this time with a shallow curve as well. Let’s say that this represents a different topic on an educational course (let’s say French because as much as I love foreign languages, I don’t get them easily!).




So for a given amount of time, will I learn most in French or mathematics?

Let’s just look at the graph again and take 8 units of time. In mathematics, I would have learned 3.5 units, whereas in French, I would have only learned around about 1!

So clearly, the steep learning curve is the one that is best, at least if you want to learn lots!

However, the use of “steep learning curve” to denote something that is difficult to learn is quite common and almost ingrained: I catch myself using the phrase this way sometimes! So maybe we would be best leaving such phrases and just be direct (i.e., just say “it’s hard to learn")?

Here a link to the Campaign for Plain English for those interested.


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