I am offering ten principles for writing material for educational courses. Principle five discusses the use of diagrams.

1. Principle 5
Diagrams
Glenn Martin
March 2017

2.  If using diagrams, ensure that all elements of the
diagrams serve to convey the meaning required,
and the relationships between the elements
accord with the meaning intended.

3.  A diagram is a sentence in a
graphical language.
 The purpose of diagrams is to
enhance understanding over
and above what is conveyed by
text.

4.  A “good” diagram is one which communicates
effectively.
 Communication (or cognitive) effectiveness is
measured by the speed,
ease and accuracy with which
the information content can
be understood.
(“The ideal career”)

5.  What looks good is not always
what communicates most
effectively, but aesthetics can
support and enhance the
message.

6.  Diagrams (and illustrations) can be used to
provide an overview of a topic (the “big picture”).

7.  Diagrams can be used to give a
more detailed account of specific
situations, dynamics and
processes.

8.  Diagrams are built up using shapes, lines,
arrows and text, which may vary in colour,
texture and size (and fonts, for text).
 Elements are chosen and combined to show
relationships, position and movement.
Graphics Meaning

9.  Check for ambiguity, relevance, logic and
consistency.