How to Read a Technical Paper

by Jason Eisner (2009)

Multi-pass reading

Skim the paper first, skipping over anything that would take much mental effort. Just get an idea of where the paper is going, why it was written, what's old hat and what's new to you. To force yourself to keep moving, give yourself a limited time budget per page or use the autoscroll feature of your PDF reader.

Now, assuming the paper still seems worthwhile, go back and read the whole thing more carefully.

Why not practice on this webpage? Go ahead, skim it first.

S. Keshav describes three-pass reading in detail: What are you trying to do on each pass?

Write as you read

Write as you read. This keeps your attention focused and makes you engage with the paper.

Low-level notes

Often it is easiest to scribble notes on the printed-out paper itself, responding in context to the formulas, figures, and text. In that case, file or scan your annotated copy for future reference.

(Or perhaps annotate the PDF file directly, without printing or scanning. A free alternative to Acrobat is PDF-XChange Viewer, a Windows program that can also be run on Linux via wine.)

You can use notes on the paper to

High-level notes

Low-level notes aren't enough. Also keep high-level notes about papers. You should try to distill the paper down: summarize the things that interested you, contrast with other papers, and record your own questions and ideas for future work. Writing this distillation gives you a goal while reading the paper, and the notes will be useful to you later.

Michael Mitzenmacher writes: "Read creatively. Reading a paper critically is easy, in that it is always easier to tear something down than to build it up. Reading creatively involves harder, more positive thinking. What are the good ideas in this paper? Do these ideas have other applications or extensions that the authors might not have thought of? Can they be generalized further? Are there possible improvements that might make important practical differences? If you were going to start doing research from this paper, what would be the next thing you would do?"

At a minimum, you should re-explain the ideas in your own words: produce some text that is aimed at your future self. You should be able to reread this later and quickly reconstruct your understanding of the paper. Don't waste time repeating the parts that are easy for you. Include a URL to the original paper, and refer as needed to the paper's Figure 1, equation (2), section 3.3, etc. But do spend time writing down hard-won bits of understanding:

"They don't say this, but equation (2) is basically the same as the method of Pookie (2001), except that they add a reconfabulation step after the data purée. I was surprised at their reconfabulator, which doesn't match what I would have expected from Kachu (2004), but it does cure the exponential growth problem in this domain. To see the difference, I found it useful to think about this example: ..."

Organizing your notes

I suggest sorting your file of notes chronologically, by when you read the paper, since that may help you find vaguely remembered papers or remember what else you were reading at the time. Sometimes you'll want to search by author/title/etc., so start the notes for each paper with a rough citation. (See also How to Organize Your Files.)

If you had to put a lot of effort into really understanding some point, you can share that effort with others (and record it for your own future reference) by improving the discussion of that point on the relevant Wikipedia page.

Many people have devised software or personal systems for annotating papers and keeping track of notes. Quora users give their recommendations here and here.

When and where to read

Start early. Leave enough time that if your attention wanders, you can put the paper down and pick it up again when you're in a better reading mood. This is better than trying to force yourself through it on a deadline.

Some people find it easier to read at particular times of day, or while eating or walking or riding an exercise bike. Do you habitually pick up the closest thing to read when you're at the breakfast table or in the bathroom? Then leave papers there for yourself.

Try reading with a friend! Sit next to each other, looking at the same copy of the paper, and stay synchronized at the paragraph or sentence level. Read aloud at times. You'll keep each other moving and help each other through the hard parts. Discuss as you go along.

Set aside time

When you are starting out in a new area, it may take you hours to read a conference paper thoroughly. That's okay. It's worth spending that much time to really understand a good or foundational paper. It will pay off in your future reading and research.

I'll never find the time! Don't worry. Not all papers take that long. Many ideas are reused across papers, so you will get faster at reading. By now, in an area I know well, I can often read a paper in 30 minutes or less, because the motivation is familiar and I can recognize much of the setup as standard practice. (After all, most papers fall into an existing tradition. They extend existing work with one or two genuine new ideas, and some supporting details that may or may not be significant.)

But I'm already a third-year student. Why is this paper taking me so long? There is no shame in reading slowly. It still takes me several hours to absorb a paper on something that I genuinely don't know well. (Also, it takes me hours to review a paper even in my own area, because the burden is on me to spot all the problems or opportunities for improvement. 75% of submitted conference papers are rejected, and most of the remaining 25% also need improvement before publication.)

Which parts to focus on

So do you really have to read the whole paper carefully on your second pass? Sometimes, but not always. It depends on why you're reading the paper.

I do think that when you are learning a new area, you should read at least some papers extremely thoroughly. That means knowing what every sentence and every superscript is doing, so that you really learn all of the techniques used in the paper. And understanding why things were done as they were: ask yourself dumb questions and answer them. Practice the ability to decode the entire paper—as if you were reviewing it critically and trying to catch any errors, sloppy thinking, or incompleteness. This will sharpen your critical thinking. You will want to turn this practiced critical eye on yourself as you plan, execute, and write up your own research.

However, there will also be occasional papers where it is not worth reading all the details right now. Maybe the details are of limited interest, or you simply don't feel equipped to understand them yet. Consider the parts of a typical paper:

In short, invest your time wisely. Focus on what is valuable to take away. If you can't figure out which parts of the paper are most "interesting" or "important," do ask someone who should know! If you don't know who to ask, find other papers that cite this one (via Google Scholar) and see what they say about this paper.

Delip Rao suggests: "Never read the original paper on X first. Instead read several later papers on what they say about X, get an idea of X and then read the original paper. Somehow the research community is much better in explaining ideas clearly than the original authors themselves."

What to read


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Jason Eisner - jason@cs.jhu.edu (suggestions welcome) Last Mod $Date: 2015/07/06 16:20:25 $