data-architecture-a

understand. When it comes to design, the most important fundamental is to ensure the
context of the visualization is understood by the user. Before the design step, it's
important to have followed the methodology and have the define and the data steps
understood. Choosing the appropriate chart requires an understanding of the data
properties and purpose for the visualization.

Forms of Visualizations

When the business need or problem is understood and the data have been gathered, the
visualization can be designed. There are many different forms of visualizations that can
be used depending on the data, but choosing the right visualization to improve the user
experience in telling the story is important. All visualizations should include not only the
visual that represents the data but also additional information such as labels and text so
the audience can understand the content and the context. Table 18.1.3 shows some basic
forms of visualizations that can be used. Some of these charts can be enhanced; for
example, a time element can be used for a bubble chart to show changes over time.
Examples for some common basic charts will be discussed. However, there are many
different forms of visualizations that should be reviewed before designing a visualization.

Table 18.1.3

Forms of Visualizations

Visualization

Form

Number of

Categories

Number of

Numerical

Variables

Purpose Audience Ease ofInterpretation Example

Number chart 1 Display Easy Average rating or score

Pie chart 1 1 Proportion comparison Easy % of negative sentiment by company

Bar chart (basic) 1 1 Showing exact values Easy Top consumer complaints aboutEquifax in a given period of time

Bar chart

(grouped side by

side)

Multiple 1 or 2 Compare categories Easy Compare hotels grouped by hotelratings

Bar chart

(Stacked) Multiple^1 Compare categories Easy

Compare hotels by on line customer

review sentiment

Line (single) 1 1 + Date variable Trends over time Easy Sales over time

Line (multiple) Multiple 1 + Date variable Compare multiple categoriesover time Difficult Consumer sentiment over time foreach credit bureau

Maps Multiple Multiple Comparing variables andgeospatial analytics Difficult Location and volume of customercomplaints

Scatter chart 0 or 1 2 Relationships and correlationsbetween numerical values Difficult Relationship between cancer ratesand country

Bubble chart 0 or 1 3 Relationships and correlationsbetween numerical values Difficult Comparing airlines by assets,revenue, and profit

Chapter 18.1: An Introduction to Data Visualizations