EFFECTIVE VISUAL COMMUNICATION OF INFORMATION IN ENGINEERING

By Clayton Chiarelott

UT Writing Center

CLEAR, CONCISE, & PRECISE

…A sentence should contain no unnecessary words, a paragraph no unnecessary sentences, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts…

(Strunk & White, 2000/1935, p. 22)

TWO WAYS OF DISPLAYING RESULTS

Tables• Numerical values and textual information

organized into columns and rows.

Figures• Any type of illustration other than a table.

• Includes charts, graphs, photographs, diagrams, etc.

PURPOSE OF DISPLAYING RESULTS

• Exploration

• Communication

• Calculation

• Storage

• Decoration

In scientific publications, the communication function is the most important.

Anything that interferes with communication is a problem

BAD TABLE

What's wrong with this one?• Too many digits as indicated by the estimated

standard errors• Ending zeros were dropped. • If the digits in 0.02229 were meaningful, then

0.02100 should be given rather than 0.021. What should have been done?• Cite standard errors rather than variances• Use the standard errors to guide you regarding

which digits to present; don't include digits that are just noise.

• Don't drop ending zeros when they are meaningful.

TEXT ALIGNMENT IN TABLES

MISLEADING FIGURES

Distortions

• Sometimes distortions occur because of errors.

• Sometimes because the artist tried to be clever.

• Sometimes because they don’t understand statistics.

The designer of the chart, Christine Chan, explained her decision on her Twitter feed, saying, "I prefer to show deaths in negative terms (inverted). It's a preference really, can be shown either way."

MISLEADING FIGURES: LIE FACTOR

• Ed Tufte of Yale University coined the term “lie factor” to describe the amount of distortion in a graph

• Defined as:

𝐿𝐿𝐿𝐿𝐿𝐿 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 = 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑜𝑜𝑜𝑜 𝑡𝑡𝑡𝑠𝑠 𝑠𝑠𝑜𝑜𝑜𝑜𝑠𝑠𝑒𝑒𝑡𝑡 𝑠𝑠𝑡𝑜𝑜𝑠𝑠𝑠𝑠 𝑠𝑠𝑠𝑠 𝑡𝑡𝑡𝑠𝑠 𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑡𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑜𝑜𝑜𝑜 𝑠𝑠𝑜𝑜𝑜𝑜𝑠𝑠𝑒𝑒𝑡𝑡 𝑠𝑠𝑡𝑜𝑜𝑠𝑠𝑠𝑠 𝑠𝑠𝑠𝑠 𝑑𝑑𝑔𝑔𝑡𝑡𝑔𝑔

• Lie factor > 1 = size of the effect is exaggerated • Don’t take too seriously; it’s a satirical formula

MISLEADING FIGURES: LIE FACTOR

DATA INK RATIO

• Above all else show data.

• Maximize the data-ink ratio.

• Erase non-data-ink.

• Erase redundant data-ink.

• Revise and editData–ink ratio = 1

DATA INK RATIO

CHARTJUNK

• Interior decoration of graphics that doesn’t tell the viewer anything new (Tufte, 1983)

• Non-data-ink or redundant data-ink

JUST SAY NO TO 3D GRAPHS

JUST SAY NO TO 3D GRAPHS

Tufte considers this one of the worst graphs ever because• it only displays 5 data

points, • it wastes a lot of space,• the top half is

inexplicably inverted,• it’s 3D, and • it has multiple clashing

colors.

Age Structure of College Enrollment

PRESENTATIONS

• Typography

• Color

• Layout

• Organization

TYPOGRAPHY

• Use a sans serif typeface such as Arial Use boldface (Arial)

• Use type sizes at least 24 points (smaller font is okay for references)

• Avoid presenting text in all capital letters

• Slide from the contractor Morton-Thiokol’s presentation to NASA about the Challenger Shuttle, which later exploded.

• Capital letters are difficult to read• Too many words for the audience to

comprehend

TYPOGRAPHY

COLOR

• Use either light type against a dark background or dark type against a light background

• Avoid red–green, blue–yellow combinations (many people cannot distinguish)

LAYOUT

• Keep text blocks, such as headlines and listed items, to no more than two lines

• Keep lists to two, three, or four items; make listed items parallel; avoid sublists, if possible

• Be generous with white space

• Limit the number of items on each slide

• Limit the number of slides so that you can dedicate at least one minute to each

ORGANIZATION

Visual depiction of the organization of a scientific presentation. • The speaker begins with

the big picture, • focuses on the work in

the middle, and• comes back to the big

picture in the end – so what?

IMPORTANCE OF VISUAL COMMUNICATION

• Visual communication is an essential skill in today’s competitive economy where marketing and presentations are important ingredients for success, for both individual and enterprises.

• The marketplace requires workers with multi-disciplinary skills, including effective visual communicators

• In some cases, effective visual communication can save lives (e.g., Challenger)

FURTHER READING

• Michael Alley The Craft of Scientific Presentations• Edward Tufte

• Beautiful Evidence• The Visual Display of Quantitative Information• Envisioning Information• Visual Explanations