Part IV Communicating findings CASE STUDY: ECONOMIC, SOCIAL AND CULTURAL RIGHTS IN AFGHANISTAN In its 2011 report on ESCR, the Afghanistan Independent Human Rights Commission (AIHRC) uses visualized data derived from interviews (see Chapter 7). For example, to illustrate demographic data about their interviewees, the AIHRC created bar and pie graphs on the ethnicity, gender and province of the individuals, as well as whether or not they identified as a “returnee” from Iran, Pakistan or other countries. Visualized data was also used to show the problems in public health services. For example, pie graphs illustrated the main categories of problems: “lack of medicine and equipment” and “no health services in our village” were two of the most frequent answers. Further, as this report is part of a series monitoring the ESCR status of Afghan citizens, the graphics offer future opportunities for time-series comparisons. 15.2. TYPES OF DATA VISUALIZATION Graphs are a visual representation of the relationship between different pieces of quantitative data (called variables). Some types of graphs illustrate some types of relationships better than others. The first question in deciding what kind of graph to use is: What is the type of relationship that you want to show? Do you want to compare one variable over time? Rank multiple variables? Show one variable as a percentage of another? Your analysis of the data (see Chapter 8) should help to answer this question. The following table provides an overview of some of the different visualization formats you can use to present the data. What do you want to do? Chart format Compare values from different variables Column or Bar Follow values over time (time series) Line Show proportional breakdowns Pie Show the interaction between two values Scatter 15.2.1. Column and bar charts Column and bar charts are the most common way to present quantitative data. They are simple to create and to understand. They are best used when comparing data from different categories. For example, you might want to show differences in the unemployment rate across age groups. Reading column and bar charts is simple. The values are usually ordered as categories on the “X” or “Y” axis (for column and bar charts, respectively). In the example below, these values are the age groups. The values are expressed as bars (horizontal) or columns (vertical) and the extent of the bars is the value. As simple as it is there are a few rules to keep in mind: • Do not overload column and bar charts. Although you can do multiple colours and multiple categories, if there are too many categories the chart becomes confusing. • Always label your axes. The reader needs to understand what units or values presented. • It is generally advisable to start your values at “0” so that the chart shows contrast in an appropriate scale. Chapter 15: Data and design: Communicating through visualization | 147