“Our networks are
awash in data. A little
of it is information. A smidgen
of this shows up as knowledge.
Combined with ideas, some of that
is actually useful. Mix in experience,
context, compassion, discipline, humor,
tolerance, and humility, and perhaps knowledge
When Al Gore rode a scissor crane up to the top of the CO2 emissions
graph in the film An Inconvenient Truth, he became a superstar of visual
communications. He compellingly used graphs to tell the story of global
warming, which helped public opinion in America to finally reach the tipping
The goal of visualization is to aid our understanding
of data by leveraging the human visual system’s
highly-tuned ability to see patterns, spot trends, and
Well-designed visual representations can replace
cognitive calculations with simple perceptual
inferences and improve comprehension, memory,
and decision making.
By making data more accessible and appealing,
visual representations may also help engage more
diverse audiences in exploration and analysis.
The challenge is to create effective and engaging
visualizations that are appropriate to the data.
Modern data graphics can do much
more than simply substitute for small
statistical tables. At their best, graphics
are instruments for reasoning about
quantitative information. Often the most
effective way to describe, explore, and
summarize a set of numbers -- even a very
large set -- is to look at pictures of those
numbers. Furthermore, of all methods for
analyzing and communicating statistical
information, well-designed data graphics
are usually the simplest and at the same
time the most powerful.
The Visual Display of Quantitative
Information, Edward R. Tufte, Graphics
Press: Cheshire, CT 1983, Introduction
The Visual Display of
Graphical Displays Should :
• show the data.
• tell the truth.
• help the viewer think about
the information rather than
• encourage the eye to
compare the data.
• make large data sets
Why should we be interested in visualization? Because
the human visual system is a pattern seeker of enormous
power and subtlety. The eye and the visual cortex of the
brain form a massively parallel processor that provides the
highest-bandwidth channel into human cognitive centers.
At higher levels of processing, perception and cognition
are closely interelated, which is the reason why the words
‘understanding’ and ‘seeing’ are synonymous.
However, the visual system has its own rules. We can easily
see patterns presented in certain ways, but if they are
presented in other ways, they become invisible... If we can
understand how perception works, our knowledge can be
translated into rules for displaying information. Following
perception-based rules, we can present our data in such a
way that the important and informative patterns stand out.
If we disobey the rules, our data will be incomprehensible or
Information Visualization, Second Edition, Colin Ware, Morgan
Kaufmann Publishers, 2004, page xxi
Good data visualisations bring pattern,
trends and exceptions to light.