Build an Affinity for K-J Method

by Craig Plain

Do you have lots of data? Written comments from surveys or focus groups? Random terms from a brainstorming session? Information you’d like to organize into manageable groups?

The affinity diagram is a great method for quickly organizing data. The tool is also known as an affinity chart, thematic analysis or the K-J method, after Japanese anthropologist Kawakita Jiro, who created the technique.

To create an affinity diagram, you’ll need index cards or sticky notes, some physical space and a group of people. From there, you can:

  1. Transfer data to the index cards or sticky notes.
  2. Scatter the cards on a table or post the notes on a wall or board.
  3. Divide the group of people into smaller groups of two or three.
  4. Have one group arrange the cards silently.
  5. Rotate the group of participants after two or three minutes. Continue this until the cards or notes are organized into groups of related ideas, issues or topics.
  6. Develop titles for each group of cards. If logical, put related groups into larger supergroups.

When you’re done, you’ll have something like the affinity diagram in Figure 1.

Completed Affinity Diagram

Following these tips will help make the process go more smoothly:

  • Write only one issue or topic on each card or sticky note.
  • Do not put the cards or notes into any type of order when setting them out.
  • Transfer the data verbatim. If possible, don’t change wording.
  • Don’t talk when arranging the cards into groups. While this might be the hardest thing to do for some, the silence keeps people from influencing others.
  • Stop the exercise when there are only a few cards left without a group. Duplicate those cards and put them into multiple groups.
  • Brainstorm to develop group headings. Post the heading labels. If some groups logically present a common theme, put them together and create a supergroup label.
  • Take time to discuss the resulting diagram. Review any surprises or disagreements that might be the foundation for an action plan.
  • Through this exercise, not only have you easily grouped the data, you also have gained the following benefits:
  • Speed: Imagine a group discussing how to compile hundreds of bits of data. The affinity exercise forces the teammembers to use instinctive reactions rather than lengthy discussions.
  • Acceptance: Reading, thinking and moving the data builds buy-in from the team. They become more familiar with issues and relationships.
  • New thinking: Because of the spatial movement, this exercise forces people to use the creative right side of the brain in addition to the analytical left side of the brain. This combination can open people’s eyes to new ways of seeing issues.

I have used this process to organize brainstorming ideas into project funnels and develop categories from a database of customer survey comments. The categories then were used to track trends and compile defects.

The amount of data being organized using this method can be intimidating. My first affinity exercise had 647 sticky notes posted all over the walls of a large conference room. It took a couple hours to complete.

Even though speed is a beneficial to the process, it is important to take your time. If there is a large amount of data and you’re having trouble forming a team for a short period of time, consider putting the cards out in a public area and letting people group the data over several days. This will allow people to tackle the project a little at a time.

Many people are reluctant to try this powerful tool. On the surface it seems a bit simplistic or even silly. But after people have completed one, they will see how useful it can be and can add it to their regular toolkit.


  1. Brassard, Michael, The Memory Jogger Plus, GAOL/QPC, 1989, pp. 17-40.
  2. George, Michael L., David Rowlands, Mark Price and John Maxey, The Lean Six Sigma Pocket Toolbook, McGraw-Hill, 2005, pp. 30-32.
  3. Tague, Nancy R., The Quality Toolbox, second edition, ASQ Quality Press, 2004, pp. 96-99.

CRAIG PLAIN is a quality leader with the GE Healthcare Institute and a lieutenant colonel helping implement process improvement at the 128th Air Refueling Wing of the Wisconsin Air National Guard. He earned a master’s degree in economics from the University of Oklahoma in 1993 and has recently completed his coursework for a doctorate in adult education. Plain is a member of ASQ.

--Abdul waris, 06-06-2016

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