Writing a technical paper

by Michael Ernst

April, 2005

Last updated: September 22, 2009


(Also see “Hints on writing an M.Eng. thesis”, by Jeremy Nimmer; my notes on reviewing a technical paper, which indicate how to recognize — and thus produce — quality work; my notes on choosing a venue for publication; and my notes on making a technical poster.)

This short document does not replace the wealth of information about writing technical papers, and about writing in general, that is available elsewhere. (In the future, I plan to add links to other resources, and suggestions are welcome.) However, this document does note several simple ways to improve your writing, by avoiding some common mistakes.

The goal of technical writing is clarity and understanding: the purpose is to communicate specific ideas, and everything about the document should contribute to this goal. If any part of the document does not do so, then delete or change that part of the document. This rule also indicates that you should know exactly what points your document intends to make; if you don't know the purpose, you cannot effectively achieve it.

Some people believe that writing papers, giving talks, and similar “marketing” activities are not part of research, but an adjunct to it or even an undesirable distraction. This view is inaccurate. The purpose of research is to increase the store of human knowledge, and so even the very best work is useless if you cannot effectively communicate it to the rest of the world. Additionally, even if you believe that you understand your ideas and contributions, you are likely to find that when you try to write or speak them, you are unable to clearly enunciate them. The process of clarifying your thinking, of which writing papers and giving talks is one aspect, is a valuable part of improving your research.


A paper should communicate the main ideas of your research (such as the techniques and results) early and clearly. Then, the body of the paper can expand on these points; a reader who understands the structure and big ideas can better appreciate the details. This advice also applies at the level of sections and paragraphs. Do not start with a mass of details, hoping that the reader will somehow figure out which of those are relevant to your main point, and only later tell the reader what the main point was.

For each section of the paper, consider writing a mini-introduction that says what its organization is, what is in each part, and how the parts relate to one another. For the whole paper, this is probably a paragraph. For a section or sub-section, it can be as short as a sentence. This may feel redundant to you (the author), but readers haven't spent as much time with the paper's structure as you have, so they will truly appreciate these signposts that help them orient themselves within your text.

Some people like to write the abstract, and often also the introduction, last. Doing so makes them easier to write, because the rest of the paper is already complete and can just be described. However, I prefer to write these sections early in the process (and then revise as needed), because they frame the paper. If you know the paper's organization and outlook, then writing the front matter will take little effort. If you don't, then it is an excellent use of your time to determine that information by writing the front matter. To write the body of the paper without knowing its broad outlines will take more time in the long run.

Do not write your paper as a chronological narrative of all the things that you tried, and do not devote space to the paper proportionately to the amount of time you spent on each task. Most work that you do will never show up in the paper; the purpose of infrastructure-building and exploration of blind alleys is to enable you to do the small amount of work that is worth writing about. Another way of stating this is that the purpose of the paper is not to describe what you have done, but to inform

The audience is interested in what worked, and why, so start with that. If you discuss approaches that were not successful, do so briefly, and typically only after you have discussed the successful approach. Furthermore, the discussion should focus on differences from the successful technique, and if at all possible should provide general rules or lessons learned that will help others to avoid such blind alleys in the future.

If you are going to introduce a strawman or an inferior approach, then say so upfront. A paper should never first detail a technique, then (without forewarning) indicate that the technique is flawed and proceed to discuss another technique. Such surprises confuse (and infuriate) readers.

Write for the readers, rather than writing for yourself. In particular, think about what matters to the intended audience, and focus on that. Do not focus on what you personally find most interesting, or what you spent the most time on, or what was most difficult, or on implementation details. (This is a particularly important piece of advice for software documentation, where you need to focus on the software's benefits to the user, and how to use it, rather than how you implemented it. However, it holds for technical papers as well — and remember that readers expect different things from the two types of writing!)

It is a very common error to dive into the technical approach or the implementation details without having appropriately framed the problem. You should first say what the problem or goal is, and — even when presenting an algorithm — first state what the output is and probably the key idea, before discussing steps. Likewise, it is better to name a technique (or a paper section, etc.) based on what it does rather than how it does it.

Writing style

Passive voice has no place in technical writing. It obscures who the actor was, what caused it, and when it happened. Use active voice and simple, clear, direct phrasing.

First person is rarely appropriate in technical writing. First person should never be used to describe the operation of a program or system. It is only appropriate when discussing something that the author of the paper did manually. (And recall that your paper should not be couched as a narrative.) It is confusing to use “we” to mean “the author and the reader” or “the paper” (“In this section, we ...”) or even “the system being described” (“we compute a graph” makes it sound like the authors did it by hand). As a related point, do not anthropomorphize computers: they hate it. Anthropomorphism, such as “the program thinks that ...”, is unclear and vague.

Be brief. Make every word count. If a word does not support your point, cut it out, because excess verbiage and fluff only make it harder for the reader to appreciate your message. Use shorter and more direct phrases wherever possible. Avoid puffery, self-congratulation, and value judgments: give the facts and let the reader judge.

Do not use words like “obviously” or “clearly”, as in “Obviously, this Taylor series sums to pi.” If the point is really obvious, then you are just wasting words by pointing it out. And if the point is not obvious (readers won't be intimately familiar with the subject matter the way the author is), then you are offending readers by insulting their intelligence, and demonstrating your own inability to communicate the intuition.

Prefer singular to plural number. In “sequences induce graphs”, it is not clear whether the two collections are in one-to-one correspondence, or the set of sequences collectively induces a set of graphs; “each sequence induces a graph” avoids this confusion. Likewise, in “graphs might contain paths”, it is unclear whether a given graph might contain multiple paths, or might contain at most one path.

Some of the suggestions in this document are about good writing, and that might seem secondary to the research. But writing more clearly will help you think more clearly and often reveals flaws (or ideas!) that had previously been invisible even to you. Furthermore, if your writing is not good, then either readers will not be able to comprehend your good ideas, or readers will be (rightly) suspicious of your technical work. If you do not (or cannot) write well, why should readers believe you were any more careful in the research itself? The writing reflects on you, so make it reflect well.


Use figures! Different people learn in different ways, so you should complement a textual or mathematical presentation with a graphical one. Even for people whose primary learning modality is textual, another presentation of the ideas can clarify, fill gaps, or enable the reader to verify his or her understanding. Figures can also help to illustrate concepts, draw a skimming reader into the text (or at least communicate a key idea to that reader), and make the paper more visually appealing.

It is extremely helpful to give an example to clarify your ideas: this can make concrete in the reader's mind what your technique does (and why it is hard). A running example used throughout the paper is also helpful in illustrating how your algorithm works, and a single example permits you to amortize the time spent explaining the example (and the reader's time in appreciating it).

A figure should stand on its own, containing all the information that is necessary to understand it. Good captions contain multiple sentences; the caption provides context and explanation. For examples, see magazines such as Scientific American and American Scientist. Never write a caption like “The Foobar technique”; the caption should also say how the Foobar technique works or what it is good for. The caption may also need to explain the meaning of columns in a table or of symbols in a figure. However, it's even better to put that information in the figure proper; for example, use labels or a legend. When the body of your paper contains information that belongs in a caption, there are several negative effects. The reader is forced to hunt all over the paper in order to understand the figure. The flow of the writing is interrupted with details that are relevant only when one is looking at the figure. The figures become ineffective at drawing in a reader who is scanning the paper — an important constituency that you should cater to!

As with naming, use pictorial elements consistently. Only use two different types of arrows (or boxes, shading, etc.) when they denote distinct concepts; do not introduce inconsistencies just because it pleases your personal aesthetic sense. Almost any diagram with multiple types of elements requires a legend (either explicitly in the diagram, or in the caption) to explain what each one means; and so do many diagrams with just one type of element, to explain what is happening.

I am not fond of having many different types of figures in a paper — some labeled “figure”, others labeled “table” or “graph” or “picture”. This makes it very hard to find “table 3”, which might appear after “figure 7” but before “freehand drawing 1”. It's best to simply call them all figures and number them sequentially; the body of each figure can be a table, a graph, a drawing, or whatever.

Your code examples should either be real code, or should be close to real code. Never use synthetic examples such as methods or variables named foo or bar. Made-up examples are much harder for readers to understand and to build intuition regarding. Furthermore, they give the reader the impression that your technique is not applicable in practice — you couldn't find any real examples to illustrate it, so you had to make something up.

Any boldface or other highlighting should be used to indicate the most important parts of a text. In code snippets, it should never be used to highlight syntactic elements such as “public” or “int”, because that is not the part to which you want to draw the reader's eye. (Even if your IDE happens to do that, it isn't appropriate for a paper.) For example, it would be acceptable to use boldface to indicate the names of methods (helping the reader find them), but not their return types.


Give each concept in your paper a descriptive name. Never use terms like “approach 1”, “approach 2”, or “our approach”, and avoid acronyms when possible. If you can't think of a good name, then quite likely you don't really understand the concept. Think harder about it to determine its most important or salient features.

Use terms consistently and precisely. Avoid “elegant variation”, which uses different terms for the same concept, to avoid boredom on the part of the reader or to emphasize different aspects of the concept. While elegant variation may be appropriate in novels or some essays, it is not acceptable in technical writing, where you should clearly define terms when they are first introduced, then use them consistently. The reader of a technical paper expects that use of a different term flags a different meaning; you will confuse the reader and muddle your point if you switch wording gratuitously. Don't confuse the reader by substituting “program”, “library”, “component”, “system”, and “artifact”, nor by conflating “technique”, “idea”, and “method”. Choose the best word for the concept, and stick with it.

Do not use a single term to refer to multiple concepts. If you use the term “technique” for every last idea that you introduce in your paper, then readers will become confused. This is a place that use of synonyms to distinguish concepts that are unrelated (from the point of view of your paper) is acceptable. For instance, you might always use “phase” when describing an algorithm but “step” when describing how a user uses a tool.

When you present a list, be consistent in how you introduce each element, and either use special formatting to make them stand out or else state the size of the list. Don't use, “There are several reasons I am smart. I am intelligent. Second, I am bright. Also, I am clever. Finally, I am brilliant.” Instead, use “There are four reasons I am smart. First, I am intelligent. Second, I am bright. Third, I am clever. Fourth, I am brilliant.” Especially when the points are longer, this makes the argument much easier to follow. (Some people worry that such consistency and repetition is pedantic or stilted, or it makes the writing hard to follow. There is no need for such concerns: none of these is the case.)

Choose good names not only for the concepts that you present in your paper, but for the document source file. Don't name the file after the conference to which you are submitting (the paper might be rejected) or the year. Even if the paper is accepted, such a name won't tell you what the paper is about when when you look over your source files in later years. Instead, give the paper a name that reflects its content.

A piece of advice that is specific to computer science (and software engineering in particular): do not use the vague, nontechnical term “bug”. Instead, use one of the standard terms fault, error, or failure. A fault is an underlying defect in a system, introduced by a human. A failure is a user-visible manifestation of the fault. (In other circumstances, “bug report” may be more appropriate than “bug”.)


Get feedback! Finish your paper well in advance, so that you can improve the writing. Even re-reading your own text after being away from it can show you things that you didn't notice. An outside reader can tell you even more.

When readers misunderstand the paper, that is always at least partly the author's fault! Even if you think the referees have missed the point, you will learn how your work can be misinterpreted, and eliminating those ambiguities will improve the paper.

Be considerate to your reviewers, who are spending their time to help you. Here are several ways to do that.

As with submission to conferences, don't waste anyone's time if there are major flaws. Ask for someone to read your paper to learn something new when you are not aware of serious problems, or in a part of the paper where you are not aware of serious problems.

It is most efficient to get feedback sequentially rather than in parallel. Rather than asking 3 people to read the same version of your paper, ask one person to read the paper, then make corrections before asking the next person to read it, and so on. This prevents you from getting the same comments repeatedly — subsequent readers can give you new feedback rather than repeating what you already knew. If you ask multiple reviewers at once, you are de-valuing their time — you are indicating that you don't mind if they waste their time saying something you already know. You might ask multiple reviewers if you are not confident of their judgment or if you are very confident the paper already is in good shape; in either case, there are unlikely to be major issues that every reviewer stumbles over.

Be generous with you time when colleagues need comments on their papers: you will help them, you will learn what to emulate or avoid, and they will be more willing to review your writing.


If you submit technical papers, you will experience rejection. In some cases, rejection indicates that you should move on and begin a different line of research. In most cases, the reviews offer an opportunity to improve the work — and you would rather have a good paper appear at a later date than a poor paper appear earlier.

There is noise in the refereeing system, and even small flaws or omissions in an otherwise good paper may lead to rejection. This is particularly at the elite venues with small acceptance rates, where you should aim your work. Referees are generally people of good will, but different referees at a conference may have different standards, so the luck of the draw in referees is a factor in acceptance.

The wrong lesson to learn from rejection is discouragement or a sense of personal failure. Many papers — even papers that later win awards — are rejected at least once, and as you return to your work, your results will improve.

Should you submit an imperfect paper? On the plus side, getting feedback on your paper will help you to improve it. On the other hand, you don't want to get a reputation for submitting half-baked work. My rule of thumb is: if you know the flaws that will make the referees reject your paper, or the valid criticisms that they will raise, then don't waste everyone's time and energy by submitting the paper. Only submit if you aren't aware of show-stoppers. You may learn of some, because reviews do often indicate concerns you did not predict ahead of time.


Use a consistent number of digits of precision. If the measured data are 1.23, 45.67, and 891.23, for example, you might report them as 1.23, 45.7, and 891, or as 1.2, 46, and 890, or as 1, 50, and 900. Use an appropriate number of digits of precision that reflects the measurement process — if you don't have confidence in the 3rd digit of precision (and there is rarely reason to have confidence in it!), omit it. Keep in mind the message you wish to convey to readers — too many digits of precision can distract readers from the larger trends and the big picture.

A related work section should not only explain what research others have done, but in each case should compare and contrast that to your work. Additionally, for each significant piece of related work, after reading your related work, readers should understand the key idea and contribution of that work.

In a 3-or-more-element list, it's better to put comma between each of the items (including the last two), for clarity. As a simple example of why, consider this 3-element grocery list written without the clarifying last comma: “milk, macaroni and cheese and crackers”. It's not clear whether that means { milk, macaroni and cheese, crackers } or { milk, macaroni, cheese and crackers }. I've seen real examples that were even more confusing.

Other resources

Norman Ramsey's Teach Technical Writing in Two Hours per Week espouses a similar approach to mine: By focusing on clarity in your writing, you will inevitably gain clarity in your thinking.

Don't bother to read both the student and instructor manuals — the student one is a subset of the instructor one — and you can get most of the benefit from his “principles and practices of successful writers”:


  1. Correctness. Write correct English, but know that you have more latitude than your high-school English teachers may have given you.
  2. Consistent names. Refer to each significant character (algorithm, concept, language) using the same word everywhere. Give a significant new character a proper name.
  3. Singular. To distinguish one-to-one relationships from n-to-m relationships, refer to each item in the singular, not the plural.
  4. Subjects and verbs. Put your important characters in subjects, and join each subject to a verb that expresses a significant action.
  5. Information flow. In each sentence, move your reader from familiar information to new information.
  6. Emphasis. For material you want to carry weight or be remembered, use the end of a sentence.
  7. Coherence. In a coherent passage, choose subjects that refer to a consistent set of related concepts.
  8. Parallel structure. Order your text so your reader can easily see how related concepts are different and how they are similar.
  9. Abstract. In an abstract, don't enumerate a list of topics covered; instead, convey the essential information found in your paper.


  1. Write in brief daily sessions. Ignore the common myth that successful writing requires large, uninterrupted blocks of time — instead, practice writing in brief, daily sessions.
  2. Focus on the process, not the product. Don't worry about the size or quality of your output; instead, reward yourself for the consistency and regularity of your input.
  3. Prewrite. Don't be afraid to think before you write, or even jot down notes, diagrams, and so on.
  4. Use index cards. Use them to plan a draft or to organize or reorganize a large unit like a section or chapter.
  5. Write a Shitty First Draft™. Value a first draft not because it's great but because it's there.
  6. Don't worry about page limits. Write the paper you want, then cut it down to size.
  7. Cut. Plan a revision session in which your only goal is to cut.

Back to Advice compiled by Michael Ernst.

Michael Ernst