visual explanations with graphs
TRANSCRIPT
Connie Malamed
@elearningcoach
theelearningcoach.com
1916 Fo
od for Young
Child
ren
1946 T
he B
asic
Seve
n
1956 A
Guid
e t
o G
ood E
atin
g
1979 D
aily
Food G
uid
e
1984 Fo
od W
heel
1992 Fo
od G
uid
e P
yram
id
2005 M
yPyr
amid
2011 M
y Pla
te
A graph makes numbers concrete and serves as a cognitive aid. Graphs show the shape of the data and can be processed in parallel. Source: BBC.
Benefits of Visualization
Makes the abstract concrete
Serves as a cognitive aid
Structures information
1
0
0
1
0
0
1
0
0
More Accurate
Less Accurate
Position Position: nonaligned Length Direction Angle
Area Volume Curvature Shading Saturation
Cleveland and McGill, 1984
Cleveland and McGill did research on which basic perceptual tasks are most likely to result in accurate judgments. So, judging position is more accurate than judging area. Tasks with the same border color provide equal perceptual accuracy.
Comparisons
4.3
2.5
3.5
4.5
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Bar Chart
2012 2013 2014 2015
When your main purpose is for the viewer to compare values, use a bar graph or a pictograph. According to the research by Cleveland and McGill, perceiving the variation in position on a common scale is relatively easy for people to do.
Bar graphs are typically used for time series data, but you can also use them to report other categories of data. Use a contrasting color or color saturation for the focus bar (if there is one). Source: Visual Design Solutions (my book).
Bar Graph
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Category 1 Category 2 Category 3 Category 4
Grouped Bar Chart
Series 1 Series 2
Use a grouped bar graph when you need to compare two or more variables in a category.
Pictographs
What problem do you see with this graph?
Answer: There is not enough differentiation between the colors.
Bar Graph
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
12
34
3D Chart
Series1
3-D bar charts can make graphs harder to read because the depth cues that show the third dimension can be distracting.
Bar Graph
4.3
2.53.5
4.5
2.4
4.41.8
2.8
0
1
2
3
4
5
6
7
8
Category 1 Category 2 Category 3 Category 4
Stacked Bar Chart
Series 1 Series 2
Stacked bar graphs are divided into independent variables or subgroups. They show the relationship of the subgroup to the total. They can be a bit difficult for making comparisons.
Trends
To show how a quantity progressively changes over time, a line graph is a good choice. This format is more effective than a bar graph when there are many data points to display. Source: Visual Design Solutions.
Do you see the difference between the quantities in this pie chart? Probably not, because it is difficult to judge area with accuracy. Use pie charts (if at all) for impact, not accuracy.
Another example of how it is difficult to judge area with accuracy.
A Side Note: This type of visualization is pretty, but is not a true information graphic. It is not a cognitive aid. It does not help us glean insights. The next slide shows another visual in this same category.
Again, this is not an information graphic in the true sense of the word. Nothing is gained from viewing it … no original or new insights.
THANK YOU
Connie Malamed
@elearningcoach
theelearningcoach.com