Information design is the practice of presenting information in a way that fosters efficient and effective understanding of it. The term has come to be used specifically for graphic design for displaying information effectively, rather than just attractively or for artistic expression. Information design is closely related to the field of data visualization and is often taught as part of graphic design courses.
Information design is explanation design. It explains facts of the world and leads to knowledge and informed action. 
The term 'information design' emerged as a multidisciplinary area of study in the 1970s. Some graphic designers started to use the term, and it was consolidated with the publication of the Information Design Journal in 1979, and later with the setting up of the related International Institute for Information Design (IIID) in 1987 and Information Design Association (IDA) in 1991. In 1982, Edward Tufte produced a book on information design called The Visual Display of Quantitative Information. The term information graphics tends to be used by those primarily concerned with diagramming and display of quantitative information.
In technical communication, information design refers to creating an information structure for a set of information aimed at specified audiences. It can be practiced on different scales.
Similar skills for organization and structure are brought to bear in designing web sites, with additional constraints and functions that earn a designer the title information architect. In computer science and information technology, 'information design' is sometimes a rough synonym for (but is not necessarily the same discipline as) information architecture, the design of information systems, databases, or data structures. This sense includes data modeling and process analysis. In the United States, the title of information designer is sometimes used by graphic designers who specialize in creating websites. The skill set of the information designer, as the title is applied more globally, is closer to that of the information architect in the U.S.
Information design is associated with the age of technology but it does have historical roots. Early instances of modern information design include these effective examples:
The Minard diagram shows the losses suffered by Napoleon's army in the 1812-1813 period. Six variables are plotted: the size of the army, its location on a two-dimensional surface (x and y), time, direction of movement, and temperature. This multivariate display on a two dimensional surface tells a story that can be grasped immediately while identifying the source data to build credibility. Edward Tufte wrote in 1983 that: "It may well be the best statistical graphic ever drawn."
Information design can be used for broad audiences (such as signs in airports) or specific audiences (such as personalized telephone bills). The resulting work often seeks to improve a user's trust of a product (such as medicine packaging inserts, operational instructions for industrial machinery and information for emergencies).
Governments and regulatory authorities have legislated about a number of information design issues, such as the minimum size of type in financial small print, the labeling of ingredients in processed food, and the testing of medicine labeling. Examples of this are the Truth in Lending Act in the USA, which introduced the Schumer box (a concise summary of charges for people applying for a credit card), and the Guideline on the Readability of the Labelling and Package Leaflet of Medicinal Products for Human Use (European Commission, Revision 1, 12 January 2009).
Professor Edward Tufte explained that users of information displays are executing particular analytical tasks such as making comparisons or determining causality. The design principle of the information graphic should support the analytical task, showing the comparison or causality.
Simplicity is a major concern in information design. The aim is clarity. Simplification of messages may imply quantitative reduction but is not restricted to that. Sometimes more information means more clarity. Also, simplicity is a highly subjective matter and should always be evaluated with the information user in mind. Simplicity can be easy when following five simple steps when it comes to information design: 1. Tell the truth. 2. Get to the point. 3. Pick the right tool for the job. 4. Highlight what is important. 5. Of course, keep it simple. These steps will help an information designer narrow down results, as well as keeping their audience engaged. 
Manage research, learning and skills at defaultLogic. Create an account using LinkedIn or facebook to manage and organize your IT knowledge. defaultLogic works like a shopping cart for information -- helping you to save, discuss and share.