What's a learning curve and why is steep not h

问题:

• What exactly is a learning curve?
• And why is it wrong to use the term "steep learning curve" for something which has high entry barriers and takes quite some time to get into?

As to the why-ness of this question:

• The terms are used often and inconsistently on Stack Overflow
• I myself have been confused by it
• Mostly the newbies are confronted with these terms when they for example ask questions like "what's the best php development framework"

回答1:

It's a curve of time versus proficiency.

Steep for hard is wrong because it'd mean that you get very proficient in very little time

proficiency
  |   __
  |  |
  |  |    Proficient in little time (steep = easy)
  |  |
  |_/____________
       time

proficiency
  |
  |       Proficient in lots of time (gentle = hard)
  |            __             
  |           /
  |__________/___
       time

回答2:

See wikipedia.

"steep learning curve" is a buzz-phrase that doesn't have any actual meaning. It used to mean that you'd make quick progress. "Over time, the misapprehension has emerged that a "steep" learning curve means that something requires a great deal of effort to learn..."

Conclusion: people who use the phrase don't know that it's unclear. You should get details from them on what specific things are hard to learn and get past the buzz-phrases and platitudes.

回答3:

(from unix.rulez.org/~calver)

_{(source: rulez.org)}

This (very unserious) diagram subscribes to the steep == "hard to climb" interpretation, for anyone keeping score. Emacs. So true. ;-)

回答4:

I've generally understood it to have more to do with the amount of time allotted to learning, and what you have to learn in that period of time. If you have only a short amount of time in which to learn something, your learning curve is going to be much steeper than if you had a longer amount of time to learn the same amount of material. So a steep learning curve IS difficult because it means you're trying to cram six months worth of learning into three weeks, or whatever.

More material in the same amount of time would produce the same curve.

回答5:

It's a battle of intuitiveness. On one hand, you've got "steep=hard to climb" association, on the other hand you have "time on the horizontal axis" convention (but "proficiency on the horizontal axis" isn't "wrong", just "less popular"). So, IMHO it's not a matter of "right" vs "wrong" but rather "intuitive" vs "more intuitive".

I think that "steep=hard to climb" will win, because it appeals to anyone who at any point in their life has climbed a stair, as opposed to the x-y curve which even people trained in mathematics sometimes mix up.

回答6:

from Widipedia:

The term learning curve refers to the graphical relation between the amount of learning and the time it takes to learn.

The term "steep learning curve" is often wrongly used for things which need some time to wrap ones mind around. Also here on Stack Overflow I've seen it used wrongly many times and hence this Question and my own answer to it.

In fact a steep learning curve is given, when it is relatively easy to start of with a new skill/technique/...

it means that the relationship between "learning progress (y)" and "time invested (x)" is greater than 1.

回答7:

There are a few possible interpretation of "learning curve", but a fairly natural one would be "time elapsed" on the X axis and "knowledge gained" on the Y axis. A steep curve, in that mapping, would imply that you gain a lot of knowledge, fast.

The only interpretation I can think of where "steep" is the same as "hard" is where you map "knowledge gained" on the X axis and "effort expended" on the Y axis and that is not a very natural mapping.

回答8:

A "learning curve" originally had total elapsed time [or total cumulative units manufactured/learned] on the X axis and the time required to produce/learn a single unit on the y axis. Your first unit always takes more time than the 100th or 1,000th. The "steepness" of the curve depends on how fast you get good at producing/learning a thing. Learn quickly and you have a "steep" curve; slowly and you have a flat curve.

I agree that the uninformed have morphed the original meaning of the term, but to be accurate steep is easy. People get upset because those of us who paid attention to using language correctly in school rarely get to take part in this type of evolution.

回答9:

Learning curve is the rate at which knowledge can can acquired. A new developer on a complex system will likely experience a steep learning curve as they will have a lot to learn before they can become productive. By implication an experienced developer may experience a shallow learning curve if they are familiar with a system.

The acquisition of knowledge does not always imply understanding. In some cases a developer may not need to absorb a lot of system detail but may need to understand underlying designs before they can be productive. This can take time but does not imply a steep learning curve.

In practise understanding and knowledge go hand in hand. Most developers will always be on a learning curve of some sort but will also be using new knowledge to forge a deeper understanding of the systems they are working as well as the tools and practises they are using.

回答10:

It's true that "steep learning curve" should mean "easy" given the origin of the learning curve as a graph of measured performance as a function of time, and that the proper expression for a hard-to-learn-task should be "gradual learning curve". But it's perfectly natural that "steep learning curve" should have come to mean "hard" given that a) most people have never looked at an actual learning curve, and b) "steep" implies "difficult" whereas "gradual" implies "easy".

This is how languages evolve, and it would be utterly futile to try and change the general usage of this term now. And, in any event, I could care less about the whole issue (see how you still knew exactly what I meant?).

回答11:

Level of difficulty is not a factor. A learning curve depicts the length of time to acquire a proficient skill set or high level of comprehension. The description will vary based on the test subject that the curve is applied to. While one can certainly say that the learning curve for acquiring proficiency of an application such as MS Notepad would be steep, another application for the curve would be the length of time individual test subject take to acquire such proficiency. The learning curve for acquiring proficiency of MS Notepad is generally steep, but it may be steeper for Mary than it is for John.

I think the key is to first understand what the curve is being applied to