Tufte s Design Principles

Transcription

1 Tufte s Design Principles CS Information Visualization January 27, 2004 John Stasko HW 2 - Minivan Data Vis What people did Classes of solutions Data aggregation, transformation Tasks - particular versus types Spring 2004 CS

2 Envisioning Information Let s hear your views on the book... Spring 2004 CS Graphical Excellence Principles Graphical excellence is the well-designed presentation of interesting data---a matter of substance, of statistics, and of design. Graphical excellence consists of complex ideas communicated with clarity, precision and efficiency. Spring 2004 CS

3 Graphical Excellence Principles Graphical excellence is that which gives to the viewer the greatest number of ideas in the shortest time with the least ink in the smallest space Graphical excellence is nearly always multivariate. And graphical excellence requires telling the truth about the data. Spring 2004 CS Leveraging Human Capabilities Data graphics should complement what humans do well Quote from top of Vol.2, page 50 Spring 2004 CS

4 Summary 1. Tell the truth Graphical integrity 2. Do it effectively with clarity, precision Design aesthetics Let s look at each of these Spring 2004 CS Graphical Integrity Your graphic should tell the truth about your data Spring 2004 CS

5 Example Stock market crash? Spring 2004 CS Example Show entire scale Spring 2004 CS

6 Example Show in context Spring 2004 CS Chart Integrity Where s baseline? What s scale? What s context? Examples: Vol. 1, page 54 (where s 0?) Vol. 1, page 54 (what s component?) Vol. 1, page 57 (change scale) Vol. 1, page 61 (change scale) Vol. 1, page 74 (show context) Spring 2004 CS

7 Watch Size Coding Height/width vs. area vs. volume Examples: Vol. 1, page 69 (area) Vol. 1, page 62 (volume) Spring 2004 CS Measuring Misrepresentation Visual attribute value should be directly proportional to data attribute value Lie factor = Size of effect shown in graphic Size of effect in data p = Spring 2004 CS

8 2. Design Aesthetics Set of principles to help guide designers Spring 2004 CS Design Principles Maximize data-ink ratio Data ink ratio = Data ink Total ink used in graphic = proportion of graphic s ink devoted to the non-redundant display of data-information Examples: Vol. 1, page 94 (good and bad) Vol. 1, page 30 (NYC weather, 2220 numbers) Spring 2004 CS

9 More... Above all else, show the data Maximize the data-ink ratio Erase non-data-ink Erase redundant data-ink Revise and edit Spring 2004 CS More... Maximize data density data density of graphic = number of entries in data matrix area of data graphic Quote from bottom of Vol. 1, page 168 Spring 2004 CS

10 Redesign charts Bar chart, scatter plot, box plot (See drawings) Spring 2004 CS Design Principles Avoid chartjunk Extraneous visual elements that detract from message Great narrative: Vol.2, bottom page Examples: Vol. 1, page 108 (shimmering display) Vol. 2, page 34 (diamonds are a girls ) Spring 2004 CS

11 Design Principles Utilize multifunctioning graphical elements (macro/micro readings) Graphical elements that convey data information and a design function Examples: Vol. 1, page (bar charts) Vol. 2, pages 36-7 (city maps) Vol. 2, page (Viet Nam Memorial) Spring 2004 CS Design Principles Use small multiples Repeat visually similar graphical elements nearby rather than spreading far apart Examples: Vol. 1, pages Consumer Reports Vol. 2, pages (trolley cars & calligraphy) Spring 2004 CS

12 Design Principles Show mechanism, process, dynamics, and causality Cause and effect are key Make graphic exhibit causality Examples: Vol. 3, pages (space shuttle) Vol. 3, page 144 (fall in river) Spring 2004 CS Design Principles Escape flatland Data is multivariate Doesn t necessarily mean 3D projection Examples: Vol. 2, page 12 (Japan guide) Vol. 2, page 24 (Java railroad) Vol. 3, pages (history of music) Spring 2004 CS

13 Design Principles Utilize layering and separation 1+1 = 3 or more Good or bad Examples: Vol. 2, page 54 (copier assembly) Vol. 2, pages 61-2 (1+1 = 3) Spring 2004 CS Design Principles Utilize narratives of space and time Tell a story of position and chronology through visual elements Examples: Vol. 1, page 43 & Vol. 2, page 110 (life of beetle) Vol. 2, pages (air flight schedules) Spring 2004 CS

14 Design Principles Content is king Quality, relevance and integrity of the content is fundamental What s the analysis task? Make the visual design reflect that Integrate text, chart, graphic, map into a coherent narrative Spring 2004 CS Graph and Chart Tips Avoid separate legends and keys -- Just have that information in the graphic Make grids, labeling, etc., very faint so that they recede into background Examples: Vol. 2, page 54, 63 Vol. 3, page 74 Spring 2004 CS

15 Using Color Effectively The often scant benefits derived from coloring data indicate that even putting a good color in a good place is a complex matter. Indeed, so difficult and subtle that avoiding catastrophe becomes the first principle in bringing color to information: Above all, do no harm. Spring 2004 CS Proper Color Use To label To measure To represent or imitate reality To enliven or decorate Spring 2004 CS

16 Color Examples Good Vol. 2, page 80 Swiss mtn map Vol. 2, page 91 or Vol. 3, page 76 Japan sea map (Bad on Vol. 3, page 77) Bad Vol. 1, page 153 US rate map Great description Vol. 2, page 82 US rate map Vol. 2, page 88 Computer screens Great quote Spring 2004 CS Guides for Enhancing Visual Quality Attractive displays of statistical info have a properly chosen format and design use words, numbers and drawing together reflect a balance, a proportion, a sense of relevant scale display an accessible complexity of detail often have a narrative quality, a story to tell about the data are drawn in a professional manner, with the technical details of production done with care avoid content-free decoration, including chartjunk Spring 2004 CS

17 Information Overload Text from top of Vol. 2, page 51 Clutter and confusion are failures of visual design, not attributes of information. Spring 2004 CS Minard graphic size of army direction latitude longitude temperature date Spring 2004 CS

18 Graphical Displays Should Show the data Induce the viewer to think about substance rather than about methodology, graphic design the technology of graphic production, or something else Avoid distorting what the data have to say Present many numbers in a small space Make large data sets coherent Encourage the eye to compare different pieces of data Reveal the data at several levels of detail, from a broad overview to the fine structure Serve a reasonably clear purpose: description, exploration, tabulation, or decoration Be closely integrated with statistical and verbal descriptions of a data set Spring 2004 CS Upcoming Interaction and Dynamic Queries (2 days) Reading Chapter 5 Shneiderman Commercial Systems assignment due in a week Spring 2004 CS

19 Sources Used E. Tufte, The Visual Display of Quantitative Information E. Tufte, Envisioning Information E. Tufte, Visual Explanations Spring 2004 CS