组织论文

Terence Tao 2007-05-06

组织论文

我一直认为计划是无用的,但规划是必不可少的。 (德怀特·艾森豪威尔,引自《六次危机》)

应该对论文的逻辑布局进行一些思考;意识流格式,即按照作者想到结果的顺序来呈现结果,通常是非常糟糕的想法,因为它们给人一种粗心大意的印象,并且读者或审稿人很难理解(或欣赏)。

例如,对于主要论点并非严格必要的外围结果应该移到评论、脚注或讨论部分。

对于主要论点必要但与论文其余部分性质非常不同的结果(例如,它们使用了来自不同数学领域的材料,或者完全由枯燥的计算组成),可以放在附录中。

每当论证中出现重大转折点,或者转向论证的不同组成部分时,应该开始一个新的部分;相反,一组密切相关的事实可能应该放在同一个部分内。

只要可能,论证中的每个主要里程碑都应该形式化为一个自包含且位置突出的命题或定理,以便于对论证进行”高层次”理解,并让读者能够在心理上将论证划分为更简单的不相互作用的组成部分。(另见”创建引理”。)一般来说,如果这些里程碑相对较早地出现在论文中(特别是,在该里程碑证明涉及的所有技术细节出现之前),可读性会得到提高,这样读者在阅读过程中就能对正在发生的事情有所了解。(那些直到论证的最后一页才出现关键结论的论文,当最终所有在整篇论文中开发的数十个神秘而技术性的数学片段最终被组装起来做有用的事情时,读起来往往特别令人沮丧,因为”大局观”在几乎整篇论文中都会缺失。)另见”激发论文动机”。

尝试将相关的部分分组在一起;例如,引理X的陈述和证明理想情况下应该放在引理X实际使用的地方附近(特别是如果该引理在整个论文中只使用一次的话)。

作为一般规则,论文中技术性较强的部分应尽可能推到论文的后面,以减轻读者的”学习曲线”。当读者处于论文的前面部分时,他或她还不完全熟悉你的符号约定和技术,因此最好用一些相对容易且具体的进展来”奖励”他或她,使其朝着主要结果前进;到论文结束时,读者将更了解正在发生的事情,并且更有能力处理论文中较困难的部分。

当然,执行所有这些建议可能需要一些初步的规划和思考,并可能需要对论文的初稿进行一些重大的重新排列,但使用现代文本编辑器(尤其是使用LaTeX,它具有自动定理编号和类似工具来促进这种重新排列),这并不像过去那样困难,并且它确实显著提高了论文的可读性(从而提高了影响力)。

在重新组织特别大而复杂的论文时,有时绘制论文的逻辑图会有所帮助。一种方法是找到最大的黑板,为每个引理或定理画一个框,为每个逻辑推理画一个箭头(例如,如果定理13使用了引理4和引理7,则从引理4和引理7的框画箭头指向定理13的框。由于能够擦除和重画来移动框和箭头,黑板比纸更适合这样做。)通过这样做,应该能够发现论文中的关键里程碑,以及哪些引理会自然地分组到各个部分或附录中。

我发现,如果你首先编写一个快速原型,组织论文也会变得更容易。

Organise the paper

I have always found that plans are useless, but planning is indispensable. (Dwight Eisenhower, quoted in “Six crises”)

Some thought should be given as to the logical layout of the paper; a stream-of-consciousness format, in which results are presented in the order in which they occurred to the author, are generally a very bad idea, as they project an image of carelessness and are hard to follow (or enjoy) by readers or referees.

For instance, peripheral results which are not strictly necessary to the main argument should be moved to remarks, footnotes or discussion sections.

Results which are necessary to the main argument, but which are very different in nature from the rest of the paper (e.g. they use material from a different field of mathematics, or consist entirely of dull computations), may be placed in an appendix.

Each time there is a major turning point in the argument, or a shift to a different component of the argument, one should start a new section; conversely, a collection of closely related facts should probably be placed within a single section.

Whenever possible, each major milestone in the argument should be formalized in a self-contained and prominently located proposition or theorem, in order to facilitate a “high-level” understanding of the argument, and to allow the reader to mentally divide the argument into simpler non-interacting components. (See also “[Create lemmas](“Create lemmas”).) Generally speaking, readability is improved if these milestones are placed relatively early in the paper (and, in particular, before all the technical details involved in the proof of that milestone have appeared yet), so that the reader has some idea what is going on during the reading process. (Papers in which the punch line is delayed until the very last page of the argument, when finally all the dozens of mysterious and technical pieces of mathematics developed throughout the paper are finally assembled to do something useful, tend to be particularly frustrating to read, as the “big picture” will be absent for almost all of the paper.) See also “[motivate the paper](“motivate the paper”).

Try to group related sections together; thus for instance, the statement and proof of lemma X should ideally be placed close to where lemma X is actually used (especially if the lemma is only used once in the entire paper).

As a general rule, the more technical components of the paper should be pushed to the back of the paper if possible, in order to ease the “learning curve” for the reader. When the reader is near the front of the paper, he or she will not yet be fully comfortable with your notational conventions and techniques, and so it is best to “reward” him or her with some relatively easy and tangible progress towards the main results; by the end of the paper, the reader will have more of an idea what is going on, and will be more capable of handling the more difficult parts of the paper.

Of course, executing all of these suggestions may require some initial planning and thought, and possibly some significant reshuffling of the paper from its first draft, but with modern text editors (and especially with LaTeX, which has automatic theorem numbering and similar tools to facilitate this reshuffling) this is not as difficult as it used to be, and it does significantly increase the readability (and hence influence) of your paper.

When reorganising a particularly large and complex paper, it is sometimes helpful to diagram the logic of the paper. One way to do this is to take the largest blackboard one can find, and draw a box for each lemma or theorem, and an arrow for each logical deduction (e.g. if Theorem 13 uses Lemma 4 and Lemma 7, draw arrows from the Lemma 4 and Lemma 7 box to the Theorem 13 box. A blackboard is better than paper for this due to the ability to erase and redraw to move boxes and arrows around.) By doing so, one should be able to spot the key milestones in the paper, and which lemmas will naturally group into sections or appendices.

I find that organising a paper also becomes easier if you first write a rapid prototype.