Interaction design (IxD) is the study of devices with which a user can interact, in particular computer users. The practice typically centers around “embedding information technology into the ambient social complexities of the physical world.” It can also apply to other types of non-electronic products and services, and even organizations. Interaction design defines the behavior (the “interaction”) of an artifact or system in response to its users.

Malcolm McCullough has written, “As a consequence of pervasive computing, interaction design is poised to become one of the main liberal arts of the twenty-first century.”

The term interaction design was first proposed by Bill Moggridge and Bill Verplank in the late 1980s. To Verplank, it was an adaptation of the computer science term user interface design to the industrial design profession. To Moggridge, it was an improvement over soft-face, which he had coined in 1984 to refer to the application of industrial design to products containing software (Moggridge 2006).

In 1989, Gillian Crampton-Smith established an interaction design MA at the Royal College of Art in London (originally entitled “computer-related design” and now known as “design interactions”).

In 2001, she helped found the Interaction Design Institute Ivrea, a small institute in Northern Italy dedicated solely to interaction design; the institute moved to Milan in October 2005 and merged courses with Domus Academy. Today, some of the people originally involved with IDII have now set up a new institute in Copenhagen, called the Copenhagen Institute of Interaction Design or CIID. Today, interaction design is taught in many schools worldwide.