If you look up the word interface you get a few definitions. One is “a common boundary or interconnection between systems, equipment, concepts, or human beings.” Another is “communication or interaction.” When you look up interaction you find “reciprocal action, effect, or influence.” Strictly looking at definitions, this shows the confusion in trying to separate interface and interaction.
It seems to me that thirty years ago interaction and interface were the same thing. Using command line-style syntax to get a computer to do what you wanted it to do was the way of both interacting and interfacing with the machine. Jeff Rulifson and Larry Tesler spearheaded the idea of creating icons, based on semiotics, to separate the two. The interface became graphic (GUI) while the interaction became point-and-click, using Doug Engelbart’s mouse. Interestingly, the desktop paradigm of the 1970s remains to this day, its successful design being suggested by its longevity.
Today we still employ a desktop as our interface, and our interactions remain those of a 1970s office. The icons for the files, folders, and trash/recycle can have not dramatically changed over these decades aside from a higher pixel count and nicer drop shadows. A small trash can is used as the delete function even on today’s high-tech touchscreen devices like the iPad. This continued implementation of the model, and its overall success, can be strongly credited to the participatory design that was initiated and advanced by Larry Tesler. As Donald Norman has suggested, “designers are not typical users.” (In this case, the designers were the programmers.) In many design problems, like these, the solution-creators are too close to the solution and too far from the problems. That is to say, they are intimate with the solution, and, as designers, they are not typical users and are therefore unfamiliar with daily problems. Participatory design was the bridge that spanned the gap between the users, with their invaluable knowledge of the problems, and the designers/programmers, with their solution-building knowledge. This collaborative effort to combine the expertise of the two sides seems like an idea that should have been implemented many years before.
Participatory design is still a common strategy when approaching design solutions. Focus groups, usability experts, programmers, and designers combine their knowledge and efforts to best create the interfaces that support the interactions necessary for the users. These efforts have created new machines that are continually closing the communication (interaction) gap between the users and the machine, like the iPad and tablets.
I feel like an attempt at suggesting what interfaces and interactions might be like in two decades would expose me as the simpleton I am. However, if I can play off the “inter” prefix of the words we are looking at, I think “intertuitive” is a concept we might see in the future. (Yes, I made that up, it’s not a misspelling.) I would suggest that this idea is a combination of interplay and intuitive. How the user interacts with the machine/device, the interplay, would be recorded and processed in order to develop interfaces, the intuitive, that cater to the users typical modus operandi. In this way, “intertuitive” machines would simplify and streamline the communication between the user and the device on, essentially, a case-by-case basis.