Ishikawa diagrams are named after Professor Kaoru Ishikawa of Tokyo University, a highly regarded Japanese expert in quality management.

“He first used it in 1943 to help explain to a group of engineers at Kawasaki Steel Works how a complex set of factors could be related to help understand a problem. [Cause and Effect] CE Diagrams have since become a standard tool of analysis in Japan and in the West in conjunction with other analytical and problem-solving tools and techniques.
CE Diagrams are also often called Ishikawa Diagrams, after their inventor, or Fishbone Diagrams because the diagram itself can look like the skeleton of a fish.” HCi Professional Services, Australia.

Kam Cheong Wong has described the use of such diagrams to assist learning about cause and effect in medicine (1). He concludes that:

“Rare but critical cases should be studied and included in an Ishikawa diagram to remind clinicians of relevant information during their clinical reasoning processes.”

… and cites an example case (2) from BMJ Case Reports that provides an example for a diagram about secondary amenorrhoea.

I think these types of diagrams are very helpful as are concept maps in general. The Ishikawa diagrams are particularly interesting since they are so focussed on cause and effect and, as Dr Wong argues, enable the linking of concepts in case reports to other forms of documented causes and effects.

1. Wong KC. Using an Ishikawa diagram as a tool to assist memory and retrieval of relevant medical cases from the medical literature. Journal of Medical Case Reports. 2011;5(1):120. Available at: http://www.jmedicalcasereports.com/content/5/1/120. Accessed April 21, 2011.

2. Bhansali A, Shanmugasundar G, Walia R, Santosh R, Dutta P. Acute abdomen and hypothyroidism. Case Reports. 2009;2009(jun08 1):bcr1220081356-bcr1220081356. Available at: http://casereports.bmj.com/content/2009/bcr.12.2008.1356.full. Accessed April 26, 2011.