这是时间与熟练度的曲线。

陡峭的路对于困难的人来说是错误的，因为这意味着你在很短的时间内变得非常精通。

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

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

请查看维基百科。

“陡峭的学习曲线”是一个没有实际含义的流行语。它曾经是指你会快速取得进展。随着时间的推移，“陡峭的”学习曲线的误解已经出现，意思是某物需要花费大量精力去学习...

结论：使用这个短语的人并不知道它是含糊不清的。你应该向他们获取具体信息，了解哪些方面是难以学习的，并且避免使用空洞的语言和陈词滥调。

(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. ;-)

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.

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.

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.

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.

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.

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.

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?).

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