Affinity Diagram

What is an Affinity Diagram?

An affinity diagram, also known as the KJ method, is a visual organizational tool used to sort a large number of ideas into smaller, related groups. It helps in identifying relationships among ideas, making it easier to organize and consolidate information, especially during brainstorming sessions. This technique is valuable for breaking down complex information into manageable sections, enhancing clarity and collaboration among team members.

The Basic Idea

Imagine you’re shopping at a grocery store. You work your way through the aisles with your shopping list, picking up chicken breasts in the meat department, lettuce in the produce section, followed by some Cheerios in the breakfast foods. Next on your list is ground beef. Now you have to go back to the meat department, wasting time going back and forth between opposite ends of the store.1

Looking back, if you had originally organized your shopping list into categories, you would have been a more efficient shopper. An affinity diagram would help you do just that! 

Affinity diagrams are visual representations that break down complex information into discrete elements, demonstrating connections between pieces of information. A basic affinity diagram might have one layer—for example, breaking down your shopping list by department. However, affinity diagrams can be more complex and include a hierarchy—such as first breaking down your shopping list by department, and then by aisle. 
Here are the steps to create an affinity diagram, usually leveraged during a brainstorming session:2

  1. Identify the issue or problem you are looking to solve with your team: Before you dive into brainstorming, it is important that everyone is aligned on the goal of the exercise. 
  2. Record each idea on a sticky note or card: It is important to allow ideas to flow loosely at this stage to promote creative and innovative ideas.
  3. Look for ideas that seem relevant for categorizing: Team members can simultaneously sort ideas independently and silently, allowing for multiple perspectives to be openly shared afterward. 
  4. Achieve consensus on the groupings: There may be differing opinions about which category an idea goes into. Use this step to discuss as a team and come to a resolution. There may be some notes that do not intuitively fit into a group—these can be left to the side for now.
  5. Create header cards for each grouping: Determine a keyword or phrase that summarizes the ideas in each group. 

Here’s an example of an affinity diagram for a team trying to improve their user experience on their company’s website:

“The art of creating an affinity diagram will allow you to distill the patterns and useful insights from the many individual quotes and data points you gather through interviews and observations.”

– Erika Hall, design consultant, in her book Just Enough Research3

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Key Terms

Abductive logic: This form of logical reasoning attempts to draw the simplest and most likely hypothesis from a set of observations. Assuming that the information is limited, which is the context in which we make most of our everyday decisions, this logic makes the most of the available information to reach a conclusion.4

Brainstorm: A creative group session where individuals spontaneously suggest ideas in order to solve a problem.

Operations Research: An analytical method of problem-solving where issues are broken down into smaller components to develop solutions that support the management of organizations.5

Total Quality Control: A management system for an entire organization focused on ensuring customer quality satisfaction and economical costs of quality.6


The affinity diagram was created by Jiro Kawakita, a Japanese anthropologist, in the 1960s, which is why it is also commonly known as the KJ method. Initially, Kawakita was looking to develop a tool that would organize information and analyze complex data sets for anthropologists. At this time, Kawakita was studying the challenges of water supply to remote valleys in Nepal’s Sikha Valley. Kawakita gathered masses of ethnographic data and was struggling to find a way to categorize them.

With masses of data spread about on my desk, I had been racking my brains to find some way to integrate them when I suddenly realized that depending on the spatial arrangement of the cards, you can see new meaning in them and find ways to systemize the data. That was the first realization that led to the creation of the KJ Method,” Kawakita said.7 

Affinity diagrams became one of the seven management tools developed by Japanese management experts after World War II. During this time, there was an increased interest in operations research in Japan focused on total quality control (TQC) for supporting their economic reconstruction. These tools were designed to address complex problems and support strategic planning.8

Total quality control was born after W. Edwards Deming, an American economist, visited Japan in 1950 to give a series of lectures on statistical methods. These statistical methods later became a cornerstone of company operations worldwide. Deming introduced the concept of the Deming Cycle, also known as the PDSA (Plan, Do, Study, Act), for continuous improvement. The affinity diagram was identified as a useful tool to leverage in the planning stage to help categorize data into themes.9

Today, affinity diagrams are used across a diverse range of fields, thanks to their versatility and simplicity. For example, businesses use affinity diagrams to develop strategic plans, categorizing business opportunities, threats, strengths, and weaknesses. UX designers use affinity diagrams to organize data from surveys, online metrics, and user interviews to identify common themes in user behavior. Affinity diagrams are even used in healthcare to organize patient feedback and clinical research data for process improvement ideas. No matter the industry, affinity diagrams are a useful tool to support teams with a range of opinions and ensure people leave a brainstorming session with more clarity and direction.


Jiro Kawakita:7

Professor and anthropologist, Kawakita was the inventor of the affinity diagram after his time spent in Nepal examining the challenges of water supply in remote mountainous regions. Kawakita continued to refine the model through further expeditions in Asia during the 1960s, teaching the structure to his students and colleagues. 

W. Edwards Deming:8 

American economist and consultant, Deming is well-known for his advocacy of quality control methods that were developed in Japan post World War II. Deming believed statistical analysis would improve quality control, and was invited to Japan in the 1950s to teach quality-control methods such as the Deming Cycle.


Affinity diagrams are a simple tool that can be used by leading organizations worldwide, providing a clear strategy for brainstorming and making decisions. Here are a few reasons why affinity diagrams are a very effective tool:

  1. They simplify complex problems. Breaking down a complex issue into smaller, manageable parts makes it easier to tackle and can be useful for delegating to different people or teams.
  2. Affinity diagrams can deal with many different types of data. Affinity diagrams are useful for data ranging from quotes collected during an interview to ideas shared during a brainstorm. They can even be used for numerical data. 
  3. It utilizes a bottom-up approach. Instead of dictating structure from the get-go, creating an affinity diagram encourages people to think creatively to come up with ideas, only having to identify a pattern afterward. This is a form of abductive logic, where reasoning moves from observations to a hypothesis.
  4. Affinity diagrams facilitate collaboration. Affinity diagrams are a useful team exercise, where team members each contribute ideas, come up with their own categorizations, and discuss the groupings together, which allows for input from different perspectives. 
  5. It demonstrates the relationship between information. One of the most important parts of creating an affinity model is determining the groups, as these create relationships between seemingly discrete data points or ideas that might not be immediately obvious, fostering greater insight into the problem at hand.7


While affinity diagrams demonstrate simple relationships between pieces of information, they aren’t as effective when you need to demonstrate multiple levels of relationships. Other tools, such as mind maps, are better suited for mapping out complex relationships and hierarchies. While the affinity diagram categorizes information, it does not provide a clear relationship of priority items, unlike a prioritization matrix, so an additional step may be required after the affinity diagram is complete. Once all the potential solutions are identified using an affinity diagram, teams would then need to determine the priority of each by identifying their impact and importance.

Additionally, complex problems are sometimes difficult to break down into small enough categories for an affinity diagram. It can also be a time-consuming exercise, having to rely on diverse perspectives and ideas to avoid groupthink. Although it is necessary for a facilitator to cultivate an environment for open communication, this can slow down how quickly a team arrives at a decision. 

Still, an affinity diagram is one of the useful tools that teams can have in their toolkit and presents an efficient first step in understanding a problem and coming up with potential solutions.

Case Studies

Using Affinity Diagrams for City Planning

As cities grow, their production and distribution of goods grow as well. However, this can lead to congestion, air pollution, and lack of public space, diminishing the quality of life for residents. As part of city logistic initiatives, municipal administrators seek to improve how goods are transported within cities for minimal negative impact on city residents and their environment. As there are multiple criteria to be considered when evaluating the effectiveness of city logistic initiatives, an affinity diagram can help municipal administrators determine a path forward.11

Two academic researchers, Anjali Awasthi and Satyaveer S Chauhan, explored how affinity diagrams could be practically applied to select sustainable city logistic initiatives for cities. A group of city logistic stakeholders, including shippers, receivers, transport operators, and public administration formed a committee to generate criteria for evaluating city logistics. Some criteria generated included “customer coverage,” “freeing of public space,” “costs,” “air pollution,” and “noise.” Next, the stakeholders grouped the criteria together, identifying four overarching criteria categories: technical, social, economic, and environmental. As a next step, the committee allocated preference ratings to each of the criteria to determine which would have the most positive impact on city logistics. 

As this case study demonstrates, affinity diagrams are a useful tool when there are multiple sets of criteria as well as stakeholders to consider. In this example, it allowed different city logistic stakeholders to have their voices and opinions heard so that they could come up with solutions for city planning that would support everyone’s needs. 

Affinity Diagrams for Public Health

Affinity diagrams are a useful tool for addressing public health problems, allowing these multifaceted and complex issues to be tackled with diverse solutions. Public health professionals need to analyze a lot of information to address community health or organizational issues in an effective manner. 

In 2010, at the National Association of County and City Health Officials, authors conducted a workshop to show the effectiveness of affinity diagrams.12 They opened with the issue statement, “How do we leverage the power and reach of public health?” and asked people to write down their ideas on post-its, which were later gathered onto a flipchart paper. The next step was to create categories, first done independently and then through discussion to reach a consensus. 

Here are some examples that were grouped together:

  • “Educate policymakers,” “Identify alternative funding sources,” and “Organize lobbying efforts” were put together under the header “Address Lack of Funding.”
  • “Health promotion and campaigns,” “Conduct social marketing focus groups,” and “Utilize social media” were put together under the header “Increase Use of Social Media”
  • “Engage stakeholders in the community,” “Get clients to tell their stories about receiving Public Health services,” and “Partner with local hospitals” were put together under the header “Develop, Utilize, and Enhance Partnerships.”

Public health professionals were then able to use the affinity diagram to tackle the issue through multiple solutions. Without the use of an affinity diagram, an individual may only consider ideas from one perspective, such as leveraging social media.

Related TDL Content

Virtual Brainstorming for an Innovation Advantage in Hybrid and Remote Work

In this article, our author Gleb Tsipursky explores how virtual brainstorming reduces some of the challenges associated with in-person brainstorming sessions, such as group size or feeling talked over. Tsipursky argues that since virtual brainstorming alleviates these challenges, it can be a more innovative and effective approach online than in-person. Thanks to tools like virtual whiteboards, affinity diagrams can be used for virtual remote sessions as well! 

Creating Great Choices with Roger Martin

Roger Martin, a strategy advisor, joins us on this podcast episode to discuss business models and how people can make great choices and move forward even when they don’t get the outcomes they hoped for. Martin and our host Brooke get into compromise, combining ideas, and taking focus off of monoliths as ways for businesses to get ahead. 


  1. “What Is an Affinity Diagram and How Do You Use It?” Miro, 29 Nov. 2023, 
  2. American Society for Quality. (n.d.). Affinity diagram. ASQ.
  3. Hall, E. (2013). Just enough research. A Book Apart.
  4. Butte College. (n.d.). Reasoning. Butte College.
  5. Rouse, M. (2021, April 28). Operations research (OR). TechTarget.
  6. DATAMYTE. (n.d.). What is total quality control? DATAMYTE.
  7. Roosen, C. (2020, July 17). What came before the affinity map? Reconsidering Professor Jiro Kawakita and the KJ method. C
  8. Kudo, N. (2012). Quality control strategy in Japan after World War II: Role of the TQC advocated by an educator W. Edwards Deming. Retrieved from
  9. Creately. (n.d.). Deming cycle: PDCA cycle and the continuous improvement model. Creately.
  10. Encyclopedia Britannica. W. Edwards Deming. Retrieved June 24, 2024, from
  11. Awasthi, A., and Chauhan, S. (2012). A hybrid approach integrating Affinity Diagram, AHP, and fuzzy TOPSIS for sustainable city logistics planning.
  12. Bialek, R., Kent, Louise., and Moran, John. (2010). Utilizing the Advanced Tools of Quality Improvement to Leverage the Power and Reach of Public Health. Advanced Tools of Quality Improvement (2nd ed.).

About the Author

Emilie Rose Jones

Emilie Rose Jones

Emilie currently works in Marketing & Communications for a non-profit organization based in Toronto, Ontario. She completed her Masters of English Literature at UBC in 2021, where she focused on Indigenous and Canadian Literature. Emilie has a passion for writing and behavioural psychology and is always looking for opportunities to make knowledge more accessible. 

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