Edward Tufte Notes

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Notes on a lecture from Edward Tufte, Palo Alto, 27 june 96	Two Deep problems Dimensionality - everything really interesting is a multivariant (multi dimensions -3 or more) question. Resolution - how much information per unit area can you present in an understandable way. (That information needs to speak to the point, not just add useless details.)
side notes	No more effective method of quality control than to have people sign their name to their work. Whenever possible avoid using keys/legends/codes, especially if only using it one time-capitalize on user's investment in learning the code. In general 1/2 of all keys can be eliminated with Direct Labels (data points-numbers, etc.-directly in appropriate locations in the graphic). Put footnotes where they belong-near the passage referring to them and not lost at the bottom of the mile long page.
On-going theme: during lecture examples were shown from many times and places	Good design ideas are indifferent to language, technology, time or method of display. Bad design reflects a deeper corruption of the thinking process-a lack of understanding of the variables involved.
Exhibit: 526 year old copy of Euclids "Elements" the definitive geometry text. reference: Envisioning Information by ET (EI from now on) page 16	Showed good and bad design points of the labelling of the triangles - you know what they look like - just like the ones in your geometry book in school. Euclid literally wrote the book about geometry. Everyone else copied him. Pointed out that this was a simple book to write from one aspect: the subject itself was limited to the same 2 dimensions available to the printed word. In chapters toward the end, 3D geometry is discussed, and in the brute force category, Euclid had pieces of paper cut out into complex shapes, prefolded, and glued to the pages with instructions for how to fold it into a model (see reference).
Exhibit: Napoleon Map by Minard Click to pop up window with a very low resolution version of the poster. Put it somewhere that you can refer to it as you read the notes. reference: The Visual Display of Quantitative Information by ET (VD from now on) page 176	Most stastical analysis tries (and often fails) to answer the question 'compared to what'. The chart was drawn up by an anti-war activist to show Napoleon's defeat in Russia and the futility of war. The top half is a map is the journey and defines the first 2 dimensions of space The width of the orange line represents the number of troops (3rd dimension) marching toward Moscow. Notice a splinter of deserters. The black line represents the troops that made it back. 10,000 of an original 420,000. The two colors define a 4th dimension of direction of motion. Along the thinning line are dates to add time as a 5th dimension. The bottom graph shows the drop in temperature (6th dimension) along the return journey. The temperature bottomed out at -30, and plotted to line up with their march.
What makes this a good design. Note: you may want to put the Napoleon map away. When you click below a new window opens. I'm experimenting with text only pages that load quickly but have graphics available when needed.	The display needs to follow the analytic task if 'compared to what', then give the means of making the comparison visually (e.g. line width) if 'why', then display should include important causative factors (e.g. temperature) etc. Multidimensional information-6 dimensions Words, Number and Image all included in one design-clearly labeled, directly on the graphic without the use of a legend. Don't need to break the info out into tables at the back of the report. Relevance of content-he had a goal - the futility of war. "Your information stands or falls on the relevance of the content." Content Driven
Exhibit: Galileo's discovery of the rings of saturn EI pg 120	ET had a 1st edition of Galileo's book of observations written in Italian. Like 1610 or so. Nice book! Rather than setting the drawing of Saturn's rings off to the side or on a seperate page, Galileo used an in-line graphic! It is a sentence element, a visual noun, text/visual integration.
Exhibit: Chrisopher Scheiner EI p 19	Galileo also included sketches of sun spots over time, but missed more useful displays because each image was on it's own page (front and back) Chrisopher Scheiner (appropriate name) a contemporary of Galileo used the important technique of Small Multiples. By putting a series of pictures next to each other in time sequencea distinct temporal patterns emerge. Notice the resolution-the information content. 2 dimensions of space, another in time The second diagram offers an adjustment of the data to account for the motion of the the sun through the sky.
Exhibit: Chart that got Gotti off EI p 31	Small Multiples again, this graph was used by the defense in the third John Gotti trial to call into question the reputation of the witnesses. An effective graphic- it got him off, but could have included another dimension if the number of incidents of each crime were given instead of just an 'X'. Notice the charge, 3rd from the bottom. These were not nice guys. Oh yeah, Gotti did not fight off his 4th appearance in court. He is now in jail awaiting appeal.
Focus on one field-say finacial data	Assement of change is important reference: VD 74-75 1st graph-adding space down to the zero axis would add no more content. By adding more points horizontally, it puts the one downward segment into context. By the last graphic there are over 32 graphic points Credibility comes from the details reference: VD 30 all the data from the year & historic data for 100+ years. 150 number/sq.in. about 2800 total Simple architecture - Complex Information It's evil antithesis-the richly structured graph with only 4 data points Filtering out noise reference: VD 38 Data sometimes need to be normalized to see the signal. This graphs filters out several cyclic factors to see the true growth in the economy. Don't trust a display without footnotes. Source, documentation, etc. These show care and a level of craftsmanship, an integrity of data. Annotation reference: VD 56-57 (powerful!) Explanation, causes, gesture-note the thin lines that are so faint as to not be obvious, but point to the specific passages. Very powerful: Smallest Effective Difference -make changes as small and modest as possible-but don't compromise effectiveness. Statement of error Tradeoff between timeliness and accuracy. Data will be adjusted later. Tell audience the likely range of change- likely adjusments of 5% will qwell quibbling about a .1% wiggle. Don't get it original, get it right. reference: handout with telephone book fonts. See what the Wall Street Journal and NY Times do-they have solved many basic design problems. Use it! Build a portfolio of examples of excellent degin and copy ideas as appropriate. Best way to improve design efforts in an organization. Make the best ones into illustrator docs-print is still one of the highest content media available. Choice of Information architecture reference: VD ch 9 Read Chapter 9
Information content: a comparison - in this part of the lecture, ET began laying out examples in the room with information density running from very low at one side to very high on the other side. reference: 1 page handout on National Gallery kiosk	Fairly hi content when compared to typical computer screens but still low relative to paper. Many web pages use less than 25% of available screen for content by the time system level, browser level and page level 'administrative overhead' space is consumed. Few computer screens even have 1000 characters of content/screen; the paper yellow pages books present 36,000 characters/page Because of this and the low resolution of the screen, computer screens operate at 2-4% the information content of the printed page.
reference: EI p 80 Swiss map I will probably add some of the oother graphics, but the elegance of this map has to be seen in print.	about 30 times the the information content of a computer screen printed in 23 passes through the printing presses. Figure/ground interaction - 1 + 1 = 3 when you put 2 lines next to each other you not only have the lines, but the background space between them. Close spacing can cause vibration between figure and ground. Worst example: reference: EI pg 62 top. Imagine trying to read it in flight in a bouncy ship. Because the Swiss maps use smallest effective difference in use of color, more info can be overlaid. Notice the change of color of the contour lines as background color changes-very subtle yet very readable. note the direct labeling of some of the contour lines.
Information density: Some other examples ranging from highest info density at top to lowest at bottom.	Highest: Human retina: 150 megabytes at 16-18 bit color reference: VD pg 26-7 Space Chart: 6.6 million numbers (galaxies) are displayed: 150,000 numbers/sq.in. Look-up manuals (i.e. Who's Who): 56,000 char/page=300 char/sq.in. Yellow pages: 36,000 char/page=280 char/sq.in. Mobil travel catalog: ~280 char/sq.in. Computer screen: maybe 1000 char/screen Almost lowest-Overhead projector presentations (a sign of a much deeper corruption) Absolute lowest: headlines of PRAVDA during communist days-designed to be low in content. (see also-EI pg 62 for surgeons general cigarette warning. designed to be hard to read-all text around it is more apealing and attractive to the eye.) Goal: Make our displays worthy of our eyes!! (technology note: Scientific American, July 96 pg 46 gives Data Density of 3.28 Gigabits/sq.in. for new DVD 'CD'-type standard.)
reference: seperate sheet from Lancet magazine. ET's redesign of medical form.	Needed highly readable font-in practice they are printed on laser writers and may be scaled to 50% Ratyher than designing a new font that would be readable, went to a solution that already exists-phone book font-Bell Centennial 2500 to 300 numbers are displayed on one page
reference: EI pg 91	Smallest Effective Difference-again key given as well as direct labelling of contours Notice only slight changes in color needed to show depth Using the whole rainbow of colors available just to show water depth may allow for more individual steps, but the small differences in shades of blue allowed for more info to be added-like the gray lines that show the paths of the ships in the survey that got the data. By using the smallest effective difference in coloring the height and depth, more visual space remains for additional dimensions of information. evil corrollary-when everything is accented, nothing is accented.
Life & Death part 1 VD pg 24	statistics applied to disease-Cholera Deaths Plotted deaths on map and they clustered in one region. Had 'where' but not 'why'. He believed that cholera was caused by water, so he added 'X's to show locations of public wells-obvious link to one well. He had the pump handle removed, and cholera deaths plumetted. By thinking and displaying causally, he got enough leverage to stop the epidemic. This was the last large Cholera Epidemic.
Life & Death part 2 4 page brochure about shuttle disaster	the engineers all said not to launch, but because the data were organized by launch date and not by temperature, no clear causal relationship seemed to exist in the minds of the suits that made the decision to launch. R. Feynman's well publicized 'demonstration' showing the non-resiliency of the O-ring material was flawed in that their was not a similar test with warmer water.
Advice for giving a lecture	Show up early- something good is bound to happen. Adjust the mood, meet those trickling in, etc. What is the problem, who cares about it & what are the solutions? Stumble-Bum technique-a HS Math teacher doing a proof on the blackboard for a group of college math prof's makes a mistake on the second line of the proof bringing all the prof's to the front of their seats - a location they keep for the rest of the talk - waiting for that next mistake that never comes. (If you want to do this you BETTER be good!) Make something complex - simple-PGP-use a particular case, back out to show how it relates to a more general relationship and then use a second particular case to drive the point home and give a second example. [Absolute command] Give everyone in the audience at least one piece of paper to carry away with them. "The poverty of Talk" the entire content of a 22 minute newscast can be covered in the top half of the front page of the New York Times. Conceptualize your audience by what they read, where they are their backgrounds. They don't turn stupid when they come to your lecture. Conceptualize your message- if it is about motion, display motion. Audiences are precious treat them that way. Contempt for your audience will show in your presentation. Humor- as long as it is on point, and NO gratuitous insults. Watch out for the use of all-male pronouns Use care when answering questions-many are in the 'what about me' category. Blow off the questionand you alienate people. If afraid there will be no questions, or you want to lead the tone, plant a question. Signal you enthusiasm- if you believe in what you are saying let your audience see it. Finish early Practice, Practice, Practice- for a real test, videotape yourself.
Showed videotape of magic-sleight of hand	Magic is designed for disinformation, misinformation Large motions mask small ones (good reason for smallest possible differences)