Graphics that present data Quick review 1. Show the reader what s/he needs to see. 2. Plan the sequence and directionality. 3.Think about the focal point of the graphic. 4. Integrate labels, units of measurement, and information into graphic to make interpretation efficient. 5. Make the color work with the information. 6. Place graphic where it will improve reader’s comprehension of complex material. 7. Label and title all graphics. 8. Remember to edit, revise, and proofread graphics. Department of Aeronautics and Astronautics 2 And, with graphics that present data. . . 10. Don’t distort or disguise data. - Choose the appropriate graphic. - Label important events in data. - Be precise about data points. - Be sure to show error variance. - Avoid 3-D graphics, false perspectives, and “chart junk.” Department of Aeronautics and Astronautics 3 Effective tables ? Order items in a way that your viewer finds useful. ? Label columns and rows clearly and specifically. ? Align entries. (In budgets, line up on decimal.) ? In large table, use white space or horizontal rule as a guide. ? Follow conventions for labeling and displaying graphics. Department of Aeronautics and Astronautics 4 What works well? What doesn’t work? Table 3: Sources of error in aerodynamic testing. Error Source Type of Error Relative Magnitude Wall interference Systematic Large Mount interference Systematic Large Load cell accuracy Random Small Load cell noise Random Small Department of Aeronautics and Astronautics 5 Effective bar charts ? Decide if chart should display vertically or horizontally. ? Use tick marks to indicate quantities on axis parallel to bar. ? Integrate label on or next to bar except if it would be too confusing. Department of Aeronautics and Astronautics 6 East West South 0 20 40 60 80 100 Analog PT Rankine Display % C o rre c t 1st Qtr 2nd Qtr 3rd Qtr 4th Qtr Department of Aeronautics and Astronautics 7 90 80 70 60 50 40 30 20 10 0 Effective line charts ? Use tick marks to indicate quantities. ? Start axes at zero unless there is a good reason not to. Then, be scrupulous about indicating this. ? Consider labeling data points. ? Label accurately. Department of Aeronautics and Astronautics 8 Dog Food Sales $- $5,000.00 $10,000.00 $15,000.00 $20,000.00 $25,000.00 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Yum-E-Dog Yuk-E-Dog Courtesy M. Anderberg Department of Aeronautics and Astronautics 9 Effective pie charts ? Label each edge and give its percentage of whole. ? Limit number of wedges. ? Avoid 3-D. ? Use color carefully. Department of Aeronautics and Astronautics 10 Human Resources 21% General Government 10% Past Military 13% Current Military 17% Physical Resources 39% Department of Aeronautics and 11 Astronautics Effective scatter plots ? Organize nontemporal data. ? Show correlation between two variables. 0 10 20 30 40 50 60 70 80 90 100 0 4 Hours of Study R e gent s S c or e Study Hours Regents Score 3 0 5 0 2 5 6 0 7 0 1 0 2 5 7 5 1 0 7 100 3 2 1 8 7 6 5 8 9 7 8 9 5 6 8 4 Department of Aeronautics and Astronautics 12