As Tyler Pace elaborates, mention of a “material without qualities” by Eric Stolterman stirred much curiousity about its existence.   The authors of Thoughtful Interaction Design mention the material without qualities because interaction design possesses few qualities as a material. There is nothing that we can perceive as a material without qualities because those qualities are what permit us to recognize it as a material.

There are so many perceivable layers in interaction design that it becomes difficult for us to define a singular source as a material. When I was an undergraduate in computer engineering, we used wires, an electric current, resistors, capacitors, inductors and diodes on a circuit board as our materials in laboratories. In other courses, we programmed transistor-bearing chips in assembly language and created a microprocessor. Beyond assembly language and VHDL, we designed a compiler and wrote programs ranging from C to modern object-oriented code with numerous libraries. As a graduate student, I now encounter creative HCI designers working in environments that do not even require any programming experience. All these levels of abstraction and tools might make it difficult for the untrained eye to recognize the essential materials of computers.

People tend to define materials at a base level at which it can be discerned from other materials. At the philosophical level, we might recognize the ‘is’ by discerning what it ‘is not’. The world is perceived as ones and zeros at one level.  In its most minute recognizable physical form, it is the quarks and leptons that make up matter which are also the materials of hardware and information technology. But we perceive all matter as constituting these basic elements so it wouldn’t be appropriate to define materials at this subatomic level. As an engineer, it is clearly the circuitry with semiconductor transistors that distinguish computers from other materials. As a result, transistors are arguably an essential material of computers.

However, recent discoveries indicate that transistors are not the only invention that allows computing. Not to underestimate the transistor: the transistor has played a pivotal role in modern computing. Modern technology is completely dependent on it. But today, nanotechnology research has revealed promising new techniques to achieve similar outcomes without transistors. Magnetism has already been experimentally used to replace transistors in chips. Future discoveries will undoubtedly replace modern base technologies as well.  So transistors will not always be an essential ingredient permitting HCI.

HCI has potentialities limited by our own humanity, both at individual and societal levels. We have obvious constraints based on the advancement of technology, cost of development and availability of resources. But due to the increasing malleability of technology and reduction of cost, the advancement of computers and its ability to interact with all of our senses constrains the future of computers only to the imagination of human intellect. So we might look at the limits of our worldly existence and imagination as the ‘ultimate’ constraining factor and material for HCI design.

Due to its broad scope, the limits of our imagination would not be an appropriate definition as the material of HCI, which would consist of everything experiential in existence. When existential imagination is the limit, the designer is the one who constrains design more than any other constraint. The choices made are based on the designer’s vision. With imagination as the limit, the substance of a design is primarily comprised of the designer’s vision.