How to read a research paper: the three-pass method
APJ-RAISE team · · 5 min read
Reading a paper from start to end is slow and confusing. The three-pass method helps you read it in three short rounds, each one deeper than the last.
Most students read a research paper like a textbook: from the first word to the last. This is slow, and you often get lost in the details before you know what the paper is about.
A better way is the three-pass method, described by Professor S. Keshav in his short note "How to Read a Paper" (2007). You read the paper in up to three rounds. After each round, you decide if you need the next one.
Pass 1: the big picture (5 to 10 minutes)
Read only these parts:
- The title, the abstract and the introduction.
- The section and sub-section headings (skip the text under them).
- The conclusion.
- A quick look at the references. Tick the ones you already know.
After the first pass, you should be able to answer five questions, which Keshav calls the five Cs:
- Category: what type of paper is it? (a new method, a test of an existing method, a survey, …)
- Context: which other papers is it related to?
- Correctness: do the main assumptions look valid?
- Contributions: what is new in this paper?
- Clarity: is it well written?
Many times, the first pass is enough. You now know if the paper is useful for you.
Pass 2: the content (up to 1 hour)
Now read the paper more carefully, but skip the hard proofs and details.
- Look closely at the figures, diagrams and tables. Check the axis labels. Are the results clear?
- Write short notes in the margin: key points, and questions you have.
- Mark the references you have not read but want to read later.
After the second pass, you should be able to explain the main idea of the paper to a friend, with the evidence behind it.
Pass 3: the details (several hours)
Do this only for papers that really matter for your work, for example a paper you want to build on or reproduce. The idea is to re-create the work in your head: take the same assumptions and think about how you would do it. Then compare with what the authors did.
This shows you the strong and weak points of the paper, and the hidden assumptions. Keshav notes that this can take a beginner about four or five hours, and an experienced reader about one hour.
Tips for students
- Do not feel bad if you do not understand everything. Even experienced researchers use several passes.
- Read with a friend or a group. Explaining a paper to others is the best test that you understood it.
- Keep one notes file for every paper you read: title, the five Cs, and your questions.
At APJ-RAISE, reading papers together is one of the first things we do.