Choose the best graphic forms to represent your data

Great visualisation (0:36)

The four features that define a great visualisation:

• Functional 
  The shape of the graphic is adapted to the questions the visualisation should help answer.
• Beautiful 
  If it is not attractive, readers won’t stop to read and interact with it.
• Insightful
  Put your data in context.
• Enlightening 
  The information the visualisation reveals shapes the perception of the reader.

This section focusses on ‘Functional’ and ‘Beautiful'.

1) Try to objectively choose the best graphic form (2:53)

Three rules to keep in mind: (3:18)

1. Think about the audience and the publication:
   The visualisation needs to be functional but can be different in style. 
   
2. Think of the questions your graphic should help answer: 
   List the things you think your readers will try to do with the graphic. 
   This is the key question!! 
   
3. Can you understand the graphic without reading every single number? 
   The goal of visualising data is to provide access to trends and patterns in the data without having to read the data. 
   

2) Tools (5:33)

2a) Chart Suggestions:

A Thought-Starter (PDF)

• This lets you decide which graphic form is the most appropriate.

2b) Choosing Graphic Forms Based on How Vision Works 

The Functional Art – Alberto Cairo (6:56)

• A classification of types of visualisations according to how accurate the judgements based on the graphic are.
• How to use the scale for accurate comparisons.
• How to use the scale when you want to show an overview.
• Example comparing different graphic forms for accurate comparisons:
• Bar chart / Bar graph
• Bubble chart
• Choropleth map

2c) Analyse graphics that have been published (10:58)

Example - Banking on the World Bank – GOOD Magazine: (11:14)

What can you do with the graphic?

• After making the graphic attractive, you need to make it functional:
• What are you supposed to do with the graphic?
• What questions are supposed to be answered?
• Example question: What is the ranking of countries by aid given?

This graphic is not functional, it forces the reader to analyse the numbers in the graphic themselves.

• A designer needs to anticipate the readers’ questions and facilitate what their needs are. 
  Example: Anticipate readers’ needs for a ranking and provide this ranking.

How was the data for this graphic handled? There are only absolute numbers.

• This overview is incomplete, a variable is missing to make the comparison between the countries complete.
• Example: Provide the amount given per capita per country.

Representing your data involves thinking about what questions you are going to answer.

• Example: The eventual goal of the graphic seems to be to locate the different countries.

3) Improve an existing graphic (15:38)

3a) Extract the numbers from the graphic 

• Excel spreadsheet
• Google Fusion Tables 
• OpenOffice Calc

3b) Think of the questions you want to ask (16:17)

• Add the population of the countries to get relative values for comparison.  
• Divide the total amount of money by the population to get the amount per capita per country.
• Compare the money given to GDP (Gross domestic product), to get a percentage of the total GDP given.
• In which country did the amount of money given change the most between 2008 and 2009?
• Calculate the difference in percentage in 2008 and 2009.

3c) Redesign the graphic (17:51)

• The original graphic is attractive but needs to be made functional:
• Make a sketch of how to redesign the graphic.
• The first slope graph shows the amount given in absolute terms.
• Slope graphs are used to represent change over time.
• The second slope graph shows the amount in relative terms.
• The original graphic can be used if it has a purpose.
• A flow map of where the money given goes to.

4) Make more than one visualisation for your data set (20:27)

Example - World population since 1950 – Época Magazine: (20:42)

• The first representation: a bubble map to show an overview of the data (click on 'Paises - MAPA').
• This does not allow for comparisons or rankings.
• The graphic is interactive allowing you to look at different time periods.
• A second representation: the data in a table according to country ranking.
• Other tools are provided to explore the data, such as filters.
• A third representation: a line graph representation of a specific country.
• A fourth representation: a line graph comparing individual countries.

You have learned (25:07)

• To represent your data, think about what questions you want readers to answer.
• In large or interactive visualisations, it is appropriate or necessary to represent your data more than once.

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In the next module, we will deal with how to make your visualisations more insightful.

But first, I'd like to you to carry out some exercise questions. Please continue by clicking the 'Next' button below.

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Reading list:

Complete reading list for all 'Introduction to Infographics and Data Visualization courses' by Alberto Cairo 

Recommended articles for all sessions

• Infographics and visualizations as tools for the mind
• Data visualization for human perception 
• Visual encoding
• The 8 hats of data visualization design
• Graphic Cheat Sheet
• Essential collection of visualization resources
• Storytelling with data
• The narrative eros of the infographic
• Emotional data visualization
• Heroes of visualization
• A confederacy of truth-tellers