Data Visualization Methods

Aims and Scope of Data Visualization

The core aim of data visualization is to provide ways to handle information by means of the study of graphical representations thereof. This serves several goals, as follows. Large amounts of data can be compactly presented, therefore easing the user’s burden of separating important aspects from details and also reducing the time and effort required to study a given process (scalability). Nontechnical users can be shielded from complex aspects related to data acquisition and processing, so they can focus on those high-level aspects that the data capture (simplicity). Different types of users having different backgrounds are enabled to communicate and learn about a data-intensive problem based on the same (visual) medium (communication). Finally, the visual depiction of data enables finding complex patterns that one is not aware of and which are hard to find when using solely traditional data analysis methods (discovery).

Data visualization serves two main purposes. First, data can be presented to interested audiences, such as scientists, professionals, or students. In this context, the presenter uses visualization as an enabling instrument to facilitate communication, by reducing the complexity of the exposition and focusing on the essential details. This usage of visualization is the most widespread and covers presentation means as diverse as infographics, PowerPoint presentations, narrated videos, and web-based dashboards. Central to this use-case is that the presenter already knows the information to be communicated and chooses the visual instruments and presentation techniques that best suit an efficient and effective presentation. Consumers of such visualizations range from professionals and specialists to students at all education levels and, [Page 462]more generally, the grand public. This usage of visualization is also known as “presenting the known.”

A second role of data visualization addresses data exploration. The aims of the audience for this role of visualization differ from the previous one: Both presenter and public are now interested in discovering previously unknown aspects embedded in a given data collection. As such, there is a less clear difference between presenters and public, so one typically speaks about visualization users. This usage of visualization relies upon more specialized instruments, such as advanced computer programs that allow users to interactively drill down in large data collections, select specific data subsets of interest, and depict them visually by a wide range of techniques, each of which focuses on the discovery of a different kind of pattern present in the data. Consumers of such visualizations are professionals who are intimately familiar with the application domain from which the data at hand emerge and also with the aforementioned specialized visualization instruments. This usage of visualization is also known as “discovering the unknown.”

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