Graphics – Day 2

Gestalt

u early 1990 psychology theory u based on groupings and how people perceive information

Importance to design u Visual connections and relationships are very strong in how people understand u Must ensure your design follows good gestalt principles to maximize the communication

Figure-ground u Clear contrast of background and the information in front of it u Common violation u Eye works on contrast, not absolutes

Figure-ground example

Clear closure u People complete the shape of a figure

Proximity u Put related items close together and visually connect them.

Clear proximity u The image and caption relationships is clear

Symmetry u Keep the page balanced u Unbalanced work bothers people u Can violate for effect, but you must evaluate the effect (know you are doing it)

Symmetry

Type of graphic to use

Main types of graphs u Table. For data that must have exact values. People have a hard time getting trend information out of tables. u Bar graph. For discrete data. u Line graph. For continuous data. u Pie graph. For showing percentage that is parts of a whole. The parts must add up to 100% and it must make sense to think about it that way.

Tables versus graphs u Tables give exact values. u Graphs show trends u Neither work well when the person needs the other type of value.

Tables u Use headings. Make sure the person knows what each column means. u Normal design is to read across. Row is a single unit, not a column. Beware of violating this simply to fit the data on the page.

Avoid 3D graphs

2D versus 3D

Bar versus line graphs u Bar Discrete data u Line Continuous data u Not interchangeable u Not what looks best to you

Avoid overly large simple graphs

Use true scales (start at zero)

Time scales left to right

Use entire graph

Have scale make sense

Data with ranges

Same info. Different scale. Are they the same?

Change of scale width u How are these perceived differently?

Putting graphs side by side Sales Revenue in US from Sales Revenue Outside US from

Text and graph support each other u During the past four years the number of pages produced monthly by each writer has increased. In 1991, we produced 40 pages per month, in 1992 the production was 44 pages, in 1993 it was 55 pages, in 1994 it jumped to 58 pages, and in 1995 production was 60 pages per month. Figure 1 shows this change.

Text and graph support each other u Figure 1 reveals a steady increase in page production. During the past four years the number of pages produced monthly by each writer has continued to increase at a rate of about 2 pages per year. Growing from 40 pages per month in 1991 to 60 pages per month in The jump between 1992 and 1993 occurred when we switched to Frame.

Prepare a visual u Prepare a graph for an report on packs of cigarettes smoked per capita per year – – – – – –

What type of graph to use? u Yearly membership in an organization u Department budget u Output change based on voltage change u Number of errors vs. score in a video game u Points scored each year by a soccer team u Points scored each game by a soccer team u Speed of the ball vs. force of the kick

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