1. January 28 2002 The Visual Display of Quantitative Information Alyssa A. Goodman Professor of Astronomy

2. January 28 2002 Visual Displays of Quantitative Information Maps Tables Graphs Charts Illustrations & Combinations Thereof

3. January 28 2002 “Core” Principles for the Best Visual Displays (of Quantitative) Information 1.Clarity 2.Tailor to Audience 3.Optimize Display Design 4.Maximum Information, Minimum Mess 5.Consider Delivery Method (hardcopy, blackboard, web, PPT, movie vs. still)

4. January 28 2002 Questions to Always Ask What’s this “VDQI” for? –Data exploration –Hypothesis testing –Making a point –Illustrating/demonstrating an idea –Condensing information –>1 of the above (best answer) Does my display pass the “interocular impact test”?

5. January 28 2002 Data Exploration

6. January 28 2002 Hypothesis (or “Model”) Testing

7. January 28 2002 Making a Point Days “predictor” dog had a cold are marked in pink

8. January 28 2002 Illustration Area = (a x b)/2 Perimeter=a+b+c a b c c=(a 2 + b 2 ) 1/2

9. January 28 2002 Illustration

10. January 28 2002 Condensing Information

11. January 28 2002 Questions to Always Ask What’s this “VDQI” for? –Data exploration –Hypothesis testing –Making a point –Illustrating/demonstrating an idea –Condensing information –>1 of the above (best answer) Does my display pass the “interocular impact test”?

12. January 28 2002 2nd Half Tables More Sample Graphics Critiques PowerPoint

13. January 28 2002 Tables

14. January 28 2002 Tables http://lpo.dt.navy.mil/ems/weatherman/std_tbl/?rnd=

15. January 28 2002 Tables When is a table better than a graph or chart? How many independent quantities are listed in a table? –Are any of the entries “correlated”? Should they be? Is the numerical accuracy shown appropriate (# of “significant figures”)?

16. January 28 2002 More Sample Graphics

17. January 28 2002 “ Small Multiples” Galileo’s Moon

18. Data Exploration Leonardo da Vinci http://water.usgs.gov/waterwatch/

19. January 28 2002 Data Exploration

20. January 28 2002 Data Exploration http://szyzyg.arm.ac.uk/~spm/neostorm.avi

21. January 28 2002 Questions Raised by the Movie Is the Earth in danger? –Resolution and its deception potential –What is the uncertainty in the positions? –What is the time scale? Which one is Earth in the movie? –The importance of labeling (What is the coordinate system? –How is the Solar System “viewed” from above?)

22. Hypothesis Testing John Snow & the London Cholera Epidemic 1854 Reproduced from Visual and Statistical Thinking, ©E.R. Tufte 1997, based on Snow’s drawing.

23. January 28 2002 Critiques

24. January 28 2002

31. Goodman, Barranco, Wilner & Heyer 1998

32. January 28 2002 PowerPoint for Good & Evil Good Forces good handwriting Animation/overlays Clear record of presentations Color Good graphics import Easy reorganization Evil Gratuitous Graphics--too much glitz, no substance Bulleted list after bulleted list Poor graphics import (e.g. EPS) Random access Difficult Spinning things

33. 1.5 1.0 0.5 0.0 -0.5 Intensity 400350300250200150100 "Velocity" Observed Spectrum Telescope  Spectrometer All thanks to Doppler Velocity from Spectroscopy

34. Radio Spectral-line Observations of Interstellar Clouds

35. January 28 2002 1. Episodic Outflows: Steep Mass-Velocity Slopes Result from Summed Bursts Power-law Slope of Sum = -2.7 (arbitrarily >2) Slope of Each Outburst = -2 as in Matzner & McKee 2000 Arce & Goodman 2001b

36. January 28 2002 COMPLETE Preview: Discovery of a Heated Dust Ring in Ophiuchus Goodman, Li & Schnee 2003 2 pc

37. January 28 2002 …and the famous “1RXS J162554.5-233037” is right in the Middle !? 2 pc

38. Star Formation >>101 Bate, Bonnell & Bromm 2002 MHD turbulence gives “t=0” conditions; Jeans mass=1 M sun 50 M sun, 0.38 pc, n avg =3 x 10 5 ptcls/cc forms ~50 objects T=10 K SPH, no B or  movie=1.4 free-fall times

39. January 28 2002 “Core” Principals for the Best Visual Displays (of Quantitative) Information 1.Clarity 2.Tailor to Audience 3.Optimize Display Design 4.Maximum Information, Minimum Mess 5.Consider Delivery Method (hardcopy, blackboard, web, PPT, movie vs. still)

40. January 28 2002 So Many Graphs, So Little Time Graphs show relationships amongst more than one variable (“multivariate”) “Time” can be, but is not always, a relevant variable Most graphs are drawn in two dimensions A map can be considered as a very direct form of graph