Effective visualization of data is crucial and allows for quick and efficient presentation of information when done correctly.This presentation will discuss how to effectively present data and ensure it is presented in a manner that accurately conveys the message intended by the author and meets the information the audience needs to make decisions.

1. TRANSMOBILITY SOLUTIONSTM
Delivering Operational Confidence to
Transportation Systems

2. Information and Scientific Visualization
Visualizing Safety Data to Drive Effective
Decision-Making
Byron Hoy CSSI Inc.
October 1, 2014

3. This is your data.

4. Which Line Looks Longer?

5. Which Line Looks Longer?

6. 1.0 Overview
• Overview about Voluntary Safety Reporting Programs (VSRP).
○ What are VSRPs and why it is important.
○ Why is it challenging to represent the data we gather from VSRPs.
• Learn about effective display of scientific data through the use of
Perceptual Techniques.
○ Why presentation of scientific data important.
○ Being able to recognize an effective presentation of scientific data
and identity modifications to a presentation that would improve its
effectiveness.
• Consider ways to effectively display VSRP data.
○ Examine existing examples.
○ Possible future work.

7. 1.1 Leading up to VSRPs
• Aviation is an ultra-safe system. Only two fatal U.S. commercial
airline accidents have happened in ten years.
○ Data is scarce – but latent risks and hazards remain.
○ Look beyond accident data to what happens in the normal
operating state.
• Some accident data is captured electronically.
○ Flight Data, Cockpit Voice Recorders, and Operational Error
Detection Programs.
• Operators and Safety Professionals (Pilots, Mechanics, Cabin Crews,
etc.) knew safety problems were occurring that were not being
reported.
○ There was fear of retaliation.
○ Peer pressure, “That’s the way we do things here.”

8. 1.2 Voluntary Safety Reporting Programs
• We want to get a more complete picture.
○ We could capture some of “WHAT” happened; but could not
capture the “WHY” it happened.
○ We want to convert safety data into actionable items.
• ICAO advocated for non-punitive voluntary safety reporting systems.
It was looking for a confidential means to report safety events and
issues.
• Implementation of voluntary safety reporting programs (VSRPs)
began.
○ Airline Safety Action Programs (ASAP) began in last 20 years.
○ Air Traffic Safety Action Program (ATSAP) began in 2009.

9. 1.3 How does a VSRP impact Data Analysis?
• VSRP’s contain large amounts of data.
○ ATSAP is the largest single-entity VSRP in the world. There are
over 90,000 reports.
○ The size of these data sets long ago precluded gaining
understanding via presentation in text form.
• With this many data points there are new challenges to be met.
○ How do we look across the entirety of the data sets to get a total
picture?
○ How to represent the data effectively?

10. Which Center Circle Looks Larger?

11. Which Center Circle Looks Larger?

12. Which Center Circle Looks Larger
• This is easier when you know what to look for.
• The same applies with creating effective displays. Once you
know what to look for, it is easier to make effective displays.
• We have safety data that we want to display effectively.

13. 2.0 Perceptual Techniques for Creating Effective Displays
• Background:
○ Raw data is converted into a form that taps into the well-developed
abilities of the human visual system (eye and mind) to detect
trends and match patterns.
○ These trends and patterns have scientific meaning in a well-designed
visualization.
• Approach:
○ Stephen Kosslyn, a cognitive psychologist, proposes eight
principles for effective graph design.
○ Being rooted in empirical studies of the cognitive abilities of the
human visual system, these principles are much more than a
matter of taste.

14. 2.1 Psychological Principles of Effective Displays
• There are eight principles which are organized into three sets because
they play special roles in accomplishing different goals.
• A effective display should allow you to:
○ Connect with your audience.
○ Direct the reader’s attention through the display.
○ Promote understanding and memory.

15. 2.2 Connect With Your Audience
• Principle of Relevance: Communication is most effective when
neither too much nor too little information is presented.
○ Decide on exactly what message you want to convey.
○ Readers expect to see all and only the relevant information.
• Principle of Appropriate Knowledge: Communication requires prior
knowledge of relevant concepts, jargon and symbols.
○ Know your audience!
○ To communicate effectively, a display must be pitched at the right
level for the readers you wish to reach.

16. 2.3 Consider Type of Chart and Information Included
• Not everyone knows what a first or second derivative is, but everyone
understands amount!
• More people understand how to interpret a bar chart. Less people
understand how to interpret a box and whiskers graph .
Top Issues
0 100 200 300 400 500 600
Number of Reports
Issue #1
Issue #2
Issue #3
Issue #4
Issue #5
Issue #6
Issue #7
Issue #8
Issue #9
Issue #10
Issue #11

17. 2.4 Direct and Hold Attention
• Principle of Salience: Attention is drawn to large perceptible
differences.
○ The most striking aspects of a display will draw attention to
them.
○ Because of this, they should signal the most important information.
• Principle of Discriminability: Two properties must differ by a large
enough proportion or they will not be distinguished.
○ Two visual properties must differ by large enough proportions.
○ Else the reader can’t tell that they are different and will not pay
attention to one verses the other.
• Principle of Perceptual Organization: People automatically group
elements into units which they then attend to and remember.

18. 2.5 What draws your attention on this?
• The middle shaded section draws attention.
• Simple Rule: Use line charts when focus on the slope is important.
• This display shows that last quarter 2013 there was less than average
and first quarter 2014 there were more than average reports.

19. 2.6 Promote Understanding and Memory
• Principle of Compatibility: A message is easiest to understand if its
form is compatible with its meaning.
○ More is more.
○ Be careful of Perceptual Distortion.
• Principle of Informative Changes: People expect changes in
properties to carry information.
○ It is confusing and distracting to a reader if they see changes in a
display that does not have meaning.
• Principle of Capacity Limitations: People have a limited capacity to
retain and to process information.
○ People will not understand the message if too much information
must be retained or processed.

20. 2.7 Compatitibility: More is More
• There is clearly more Safety Events than Safety Incidents
• Simple Rule: Pie Charts are best used to compare three or fewer
different points of data.
○ Pie charts are typically not the best choice displaying information.
○ Do not use pie charts when there is similarity in data.
Safety Event and Safety Incidents Reports
77%
23%

21. 2.8 Which Pie Slice Looks Bigger?
• Perceptual Distortion: Angles symmetrical around the horizontal axis
> and < look larger than the exact same angle around the vertical
axis v and ^.

22. 2.9 Capacity Limitations
• We can group only so much data together and understand it.
• Simple Rule: Use bar charts when relative amount is an important
Safety Issues
0 200 400 600 800 1000 1200 1400
Number of times Category was Selected
Q3 2014
Q3 2013
Issue #1
Issue #2
Issue #3
Issue #4
Issue #5
Issue #6
Issue#7
Issue #8
Issue #9
Issue #10
factor.
• This shows that there are clearly more of Issue #1 and #2.

23. 3.0 An Analysis of a Display

24. 3.1 Analysis of a Display
• This is an Ishikawa Fishbone Diagram. (Otherwise known as a Cause-and-
Effect Diagram.)
• This type of diagram
is often used in
project management.
• It uses a non
traditional means to
convey information.
• Knowing your target
audience is important!

25. 3.2 Cause and Effect Diagram Redux
0 100 200 300 400 500 600
Speed
Altitude
Course/Routing
Factors Leading to Conflict Between IFR Aircraft

26. Summary
• VSRPs help us get a more complete picture of aviation safety events.
• Representing data is extremely important to effectively drive correct
decision making.
• To create effective displays, we want to always do the following:
○ Connect with your audience.
○ Direct the reader’s attention through the display.
○ Promote understanding and memory.
• Thank you!

27. Sources
• Olsen, Bob. Lecture notes Richard Stockton College, October 2012,
Scientific Visualization
• Kosslyn, Stephen Michael. Graph Design for the Eye and Mind. New
York: Oxford UP, 2006. Print.
• Healey, Christopher. Perceptual Techniques for Scientific
Visualization. North Carolina State University.
• BrainBashers: Optical Illusions
http://www.brainbashers.com/illusions.asp