start with…

• PURPOSE OF DATA DISPLAYS. ALL OF THEM. The reason for these displays—rather then just putting numbers in your paragraphs—is to help your readers VISUALIZE info.

• PURPOSE OF YOUR DISPLAY? What do you hope to prove with this data? How will looking at the data visually help make your point? What’s the most crucial point you need to convey with the particular data display you’re working on?

As always, purpose needs to be considered:

represent complex data in columns and rowsor as an underlying grid to arrange information

tables

show pieces of a whole; represent percentages

Figure 2: Leading Causes of Death for Youth and Adults (2003)

pie charts

used to represent one data groupsimple bar charts

used to represent more than one data group complex bar charts

used to plot interval data

line graphs

used to plot data pointsscatter plots

follow spatial contours; used to geographically/spatially represent data

data maps

data represented by picturespictograms or pictographs

bad, bad data displays

• labels are almost impossible to read

• arrangement of information makes no sense

• just because you can does not mean you should…

• 3D effects and arrangement completely obscure information

• flattened text is difficult to read and associate with the data

• pie charts are used to show percentages, but there are no percentages here

• size of pies makes it difficult to interpret data

• bar chart is absolutely unnecessary

• scale is too large for data displayed

• different types of plot lines (i.e., black line and red line) not explained

• equations clutter the chart

• is “Surveyor vs. RIPE” the title of the chart? if so, it should be in a different font face and size from the axis labels > there’s no contrast here to cue us in

• too much data!

how to lie with data displays

large scales hide changes

drastic scalingemphases changes

level of detail can obscureor reveal important information

good, descriptive labels are crucialto reveal meaning and purpose

certain formatting options canvisually overemphasize information

MON TUE WED THU FRI SAT SUN

coffee 35 10 9 29 9 29 24

Soft drinks

34 43 24 34 34 34 37

Fruit juice

34 30 39 4 34 20 12

water 42 35 15 15 34 39 35

Matching graph to purpose

Some data: Weekly Beverage Consumption

• While this does show change across time, it gives us little visual info. It doesn't really serve any purpose

Sunday Monday Tuesday Wednesday Thursday Friday Saturday0

5

10

15

20

25

30

35

40

45

50

• If the purpose of the data is to reveal trends in overall consumption, a pie chart is inappropriate. It should only be used to reveal percentages

Coffee

Soft Drinks

Fruit Juice

Water

• if the data is supposed to compare consumption across the week, a bar chart would work best

Sunday Monday Tuesday Wednesday Thursday Friday Saturday0

5

10

15

20

25

30

35

40

45

50

Coffee

Soft Drinks

Fruit Juice

Water

Sunday Monday Tuesday Wednesday Thursday Friday Saturday0

20

40

60

80

100

120

140

160

• This kind of bar chart, however, shows both a comparison of percentages and consumption across time. The most information can be determined from this chart.

1. launch Microsoft Word

1. in a new document, select Insert Picture Chart

1. create displays for the data you have decided on from the data sets online

2. Open the data entry table and enter your data; the chart will automatically be created as a bar chart.

3. Click on the “chart type” icon. Choose the appropriate chart type.

creating data displays

anatomy of a chart

anatomy of a chart

X Axis - If you have non-numerical data, it goes here

Be sure the legend is visible

Title should be large and comprehensive

Y Axis – always numerical

Last Thoughts

• While this may seem like a relatively simple set of tasks, it really is harder than one might think. It also is more time consuming that you might think. Take advantage of class time!!

• refer back to this PowerPoint to make sure you’re using the correct display for your data

• make sure to title and label your data displays appropriately (Word, Excel, and whatever other applications you use might provide some template/help with this, but you might have to access deeper features to add labels not default-offered by the application)