The Nonlinear Optics Web Site

Technical Writing

Based on reviews of hundreds of papers, proposals, and dissertations, I have found that good writing is correlated with clear thinking. Students for whom English is a second language often make grammatical mistakes. However, this does not prevent them from clearly expressing their ideas. In contrast, I have had domestic students whose writing is grammatically correct, but impossible to follow. On this page, I give my subjective advice on good writing.

Keep it Simple

Simplicity is the key to producing an understandable document. Don't use impressive or extra words to give your work the appearance of sophistication. Such writing is distracting and annoying to the reader. Instead, choose your words precisely to convey your intended meaning; and, keep the number of words to a minimum.

Grammar and Style

I recommend that every technical writer buy a copy of The Elements of Style, by Strunk and White. When in doubt, refer to this classic book. We all make grammatical errors, as I have undoubtedly made on this page, but, try keeping such errors to a minimum.

The Elements of Style (4th Edition)

Organize Your Thoughts

To produce good writing or good lectures requires that you know your audience. Before writing a single word, determine if the average reader is an expert who wants to know the details or a casual reader who wants to gain a broad understanding of your work.

In the introduction, explain the motivation for your work, reference past work that places your work into perspective, state your specific contribution to the field, and summarize your approach. Did you solve a longstanding problem, determine a piece of an important puzzle, or deepen our understanding of the physical world? Don't start writing until you can answer these questions.

Present your work in logical order and avoid afterthoughts. For example, don't say "We measured the second harmonic signal, recorded the data using an oscilloscope, then analyzed it using a Green's Function Technique. The second harmonic measurements were done using a photodiode detector." Instead, say, "We used a photodiode detector to measure the second harmonic signal, recorded the data using an oscilloscope, then analyzed it using a Green's Function Technique."

Be Your Own Toughest Critic

The most difficult part of writing is editing one's own work. I first write a paper completely, print it out, let it sit for two weeks in a file cabinet, and then edit it dispassionately with red ink. Look for errors in logic, clarity of presentation, errors in the research, grammatical errors, and typos. If red ink does not overwhelm the page, you have not done an honest job of editing.

My research advisor in grad school gave me a good tip on making sure that each sentence is properly constructed. After going through a major edit, simply re-read the manuscript backwards, starting at the end and moving upward. It is easy for the mind to wonder and gloss over several sentences when reading. The backward reading technique forces one to read every sentence.

Use the Active Voice

Be direct. Write "The boy hit the ball," Avoid writing "The ball was hit by the boy." Also, use the present tense when possible. Consider the sentence, "The measured second harmonic coefficient was 3.0 pm/V." Instead, state, "The measured second harmonic coefficient is 3.0 pm/V." If something varies with time, then it is acceptable to state, "It was warm and now it is cold."

Note that some funding agencies require passive voice and prefer, "The quantity is measured to be..." rather than "We measured the quantity to be..." If someone is paying the bills, then follow their rules!

See The Elements of Style (4th Edition) for excellent tips on good writing.

Common Errors

Generations of students make similar mistakes. Here I give several examples

Nouns, Verbs, and Word Jumbles

Each sentence needs a noun and the appropriate verb. Furthermore, each sentence needs to convey a clear and concise thought. Consider the following paragraph in the introduction to the "Results" section of a dissertation:

Numerical analysis of the theoretical models present in Chapter 2 are fitted to the experimental results. Furthermore, empirical trends are seen within the time period the data was recorded.

In the first sentence, it is difficult to identify the verb and noun associated with the point that the author is trying to make because he intertwines two separate thoughts.

The author's intention is to state that he fit experimental data to a model and that his models rely on numerical analysis. It is best to make each point in a separate sentence.

The second sentence states rather awkwardly that certain trends were observed. Thirteen words were used when 4 would have sufficed.

The author's paragraph conveys little information other than (1) data is fit to theory and (2) certain trends are observed. More details are warranted to prepare the reader for what comes next.

For example, an author should briefly answer questions such as,

  1. What hypotheses are tested with the experiments?
  2. How is the validity of each hypothesis related to the values of the parameters determined from the fit?
  3. What outstanding questions are being answered by this work.

For example, consider the following alternative:

Chapter 2 describes models of phenomenon XYZ based on the mechanisms A and B that are generally believed to be responsible. This chapter compares the experimental data with our theory using as fit parameters the variables associated with each mechanism. The importance of each mechanism is determined from these variables.

This paragraph clearly states the phenomena being studied and how the data will be used to test the hypotheses. The reader is now prepared for the details presented in the rest of the chapter.

Lazy and Sloppy

I believe that most instances of poor writing is an unwillingness of an author to take the time to carefully think about how to explain a concept. It is far easier to write a bunch of words as they pop into one's head. Consider:

It was found that the sample was independent of polarization

If I had not been familiar with the work, I would have known that he meant to say,

It was found that the TRANSMITTENCE OF LIGHT THROUGH THE sample was independent of THE LIGHT'S polarization

Clearly, the author was writing without thinking. Careful editing using the backward reading technique would have caught this problem.

The best way to become a good writer is write, write, write, and edit. Also, get others to read your manuscripts.