This page updated 3/15/2021


Cause & Effect

What is a Fishbone Diagram?


The Goal:  


You will learn a graphic organizer that is used by businesses all over the world.  The fishbone (or Ishikawa) diagram is used to solve problems of all kinds.  And remember, a problem/solution is another way to describe a cause & effect relationship.


The fishbone diagram was invented by businessman Kaoru Ishikawa in the 1960s.  He wanted his employees to have a simple tool they could use any time they needed to solve a problem.  He developed a cause & effect diagram using the idea of a fish skeleton!

The spine and head of the fish represent one part of the effects or outcomes in the relationship, and the ribs of the fish represent the underlying causes. 


Let's take a look at how the fishbone diagram can be used.

The diagram:   As you can see in the fishbone diagram below, the effect is the "head" or "spine" of the fish.  The smaller ribs show all the underlying causes that create the effect, and the "end ribs" represent categories where you can uncover the underlying causes.

The fishbone below is an example of a MANY CAUSES - ONE EFFECT.

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More about the Fishbone Diagram:  


Using the fishbone diagram is easy once you understand what the piece parts are.  It gives you structure so you can see your cause, effects, and any influencing factors that impact the outcome.  But, before you start brainstorming using a fishbone, use a checklist to be sure you have addressed the following issues

Purpose:   What are you trying to do?  Which cause/effect relationship are you presenting?

  • Trying to solve a problem?

  • Identifying why something is occurring?

  • Making a decision?

  • Trying to predict what an outcome will be?

These are the ways cause & effect can be presented, remember?  

Relationship:  You also have to know which cause/effect relationship you have?  Is it

  • One-to-One?

  • Many-to-One?

  • One-to-Many?

  • Many-to-Many?

A fishbone diagram works best for One-to-One, or Many-to-One relationships.  For the other two, there are different graphic organizers that work best.  More on these later. 


Essential Question:  Finally, you need to have a clear essential question to answer.    The best 5Ws & H to use is "Why?"  In fact, as you complete your fishbone, you may find yourself asking "why" over and over to uncover hidden causes and influencing factors. 

Categories:  Another element you need to know is "How can you break down the cause/effect into categories to help you uncover hidden causes and influencing factors?"  This will take a little "pre-brainstorming", and it is best done after you know what your essential question is. 


1.  Make a copy of the printables and the checklist.  Use them as you watch the video.

2.  When you think you understand what a fishbone diagram is and how to fill it out, go on to the Practice A Fishbone lesson.