1. Vladimir Milev Telerik Corporation
Proper usage of data visualization in dashboards and business applications
Vladimir Milev
Telerik Corporation

2. Data Visualization tools PM @ Telerik
Author bio
Vladimir Milev
Data Visualization tools Telerik
Products: Silverlight, WPF, WP7, ASP.NET, Winforms
MCPD Enterprise Application Developer
Blog:

3. About telerik

4. Agenda
Why is proper data visualization so important?
Examples of poor usage of visualization and guidelines for correct usage of data vis.

5. Why is Data Vis so Important?
On May 1st, Osama has been killed.
How did the world react to his death?

6. World response – raw data

7. World Response – Visualization

8. Anscombe’s Quartet Created in 1973 by Francis Anscombe
Statistical properties are identical:
Mean of X (9.0) and Y (7.5) values are constant
Nearly same variances, correlations and regressions I II
III IV x y 10
8.04
9.14
7.46 8
6.58
6.95
8.14
6.77
5.76 13
7.58
8.74
12.74
7.71 9
8.81
8.77
7.11
8.84 11
8.33
9.26
7.81
8.47 14
9.96
8.1
7.04 6
7.24
6.13
6.08
5.25 4
4.26
3.1
5.39 19
12.5 12
10.84
9.13
8.15
5.56 7
4.82
7.26
6.42
7.91 5
5.68
4.74
5.73
6.89

9. Anscombe’s quartet

10. Data Vis and developers

11. Data-to-ink Ratio (efficiency of graphs)
data to ink = data ink / total ink used for printing
data-to-ink = proportion of a graphic’s ink devoted to the non-redundant display of data-information
1 – data-to-ink = ratio of redundant junk ink used for visual flare. Can be erased and no useful data information will be lost.
An efficient graphic should have a data-to-ink close to 1

12. Careful with pie charts
Relative size of the pie slices is harder to determine
Bar charts are just easier to read in general

13. Careful with pie charts
Because of its shape the pie chart wastes precious screen space

14. Comparing Values With Pies

15. In defense of pie charts
Not all pie charts are bad!
Pie Charts are best at visually illustrating the proportion of a part in relation to the whole
Pie charts are also good at showing extremes

16. Careful with pie charts
Worst pie chart in the universe! 

17. Choosing the right chart for the job
Do not show relationships that don’t exist!

18. Choosing the right chart for the job
Show trends with lines, not bars

19. A word about bar charts

20. A word about bars
Bar graphs should always start at 0!
Otherwise the visual ratio between bars is skewed and incorrectly exaggerated.

21. A note about 3d graphs

22. Gauges vs Bulletgraph
Consider using bullet graphs instead of gauges.
Better readability
Higher data-to-ink ratio
Can be used inside a grid control

23. Linear vs quadratic change

24. Linear vs quadratic change
The difference between Starbucks and KFC is n.
The designer decided to stretch the graphic by n
Since it is a logo he decided to stretch in two directions…

25. Linear vs quadratic change
Scaling the area of a graph item results in a quadratic (n2) difference in the data!
The solution? If you scale area, use
A=n2
A=π*r2

26. Conclusion

27. Recommended materials
Data Driven Consulting:
Eager Eyes:
Perceptual Edge:
Juice Analytics:
Junk Charts:

28. After the session please fulfil the questionnaire.
Questions?
After the session please fulfil the questionnaire.
Questionnaires will be sent to you by and will be available in the profile section of the NT Conference website .
Thank you!