Why is the screen size of an iPhone phone basically the same as the palm area of an adult? Why does the detail menu on the computer screen pop up to the right or down? Why is the "on" key of most mechanical equipment moved upward? Why are game console manufacturers keen to develop various somatosensory control devices?
The history of technological progress is, in the final analysis, a history in which human behavior adapts to and influences new technology. So when did we start to realize that technology must be people-oriented?
It ’s not people who mess up, but design
A B17 that crashed when landing
To answer this question, we must move our eyes to more than 70 years ago. At the end of 1944, as the smoke of World War II swept the world, a young psychologist, Paul Fitz, came to the Arrow Medical Research Center near White Patterson Air Force Base in Dayton, Ohio, USA. (Paul Fitts). His job is to analyze the thousands of military aircraft accident reports accumulated on the desk.
Paul Fitts
On the surface, these accidents can be attributed to "pilot misoperation", and the reason is simple: Thousands of young Americans are recruited into the army, and after a short period of high-intensity training with greatly compressed processes, they have assumed control of various operations. The burden of complex military equipment and machinery makes accidents a matter of course. However, due to the professional habits of psychologists, after talking with many pilots who survived the accident, Fitz found that something was wrong and could not be explained simply by the pilot's lack of experience or training.
For example, the well-known American B17 "Air Fortress" four-engine bomber has had nearly 1,000 crashes caused by "pilot operation errors", of which 475 have almost the same process: the accident occurred during the landing phase, and the pilot believed that his The steps were exactly correct, but without exception, the plane stalled suddenly and then landed on the belly.
Fitz's deputy found that the reason why the pilot insisted that he had not mishandled was because in the operating system layout of the B17 cockpit, the two joysticks responsible for controlling the flaps and landing gear were not only close to each other, but also almost identical in appearance. As a result, many pilots pulled the wrong joystick when returning after completing a thrilling bombing mission, and then caused the aircraft to stall first during the landing phase and finally crash without landing gear ... In other words, this kind of The tragedy should be blamed on the poor design of the flight operating system.
Fitz therefore produced a report recommending that the dimensions of all military aircraft's joysticks and valves must be different, so that pilots can recognize them even by touch. Soon, the head of the B17's landing gear joystick was designed as a disc tire type, using rubber material; while the flap joystick maintained the original hard plastic material, with a V-shaped wedge shape.
A formula about how we interact with machines
However, Fitz and his colleagues were not satisfied with this trifling, and began to consider the relationship between industrial design and human instincts: "The manipulation of machinery should be consistent with our instinctual behavior model. If we want to make aircraft or When the vehicle turns left, the steering wheel and joystick must be set to turn to the left. If we want to activate a function, the start switch must be moved upward. "
He wrote in the report: "We have never used external devices in the best environment in the best state, but often in non-ideal states such as distraction, fear, confusion, fatigue, mood swings, etc., so any human-computer interaction The interface must be concise, clear, and highly recognizable, so that novice beginners can get started quickly after short-term training as much as possible, and to minimize operating error rates under extreme conditions. "
Fitz's Law Function Graph
In 1954, Fitz published his dissertation "Human Body Function and Target-Oriented Motion", which established a brand-new interdisciplinary subject and the birth of engineering psychology. The core is to study the internal and external factors that affect the manipulative behavior of machinery. In the paper, Fitz proposed the famous "Fitz's Law": the time required for a human to manipulate an object and move it to a specified area, and the probability of errors and deviations in this action, determined by the distance moved and the object The size is determined by the latter two constitute a complex functional relationship.
After the birth of Fitz's law, it was quickly applied to industrial design, especially in user interface design. For example, the size of the buttons of a mechanical control device must be conspicuous enough, the distance between related equipment for a single specific task must be close enough, and the shape must have significant differences. To this day, this design principle called "shape coding" is still effective in industrial design.
Adapting machines to humans? necessary!
In the 1950s, with the rapid development of military technology in the Second World War, which was widely used in the field of civilian consumption, this "human-centered interface" engineering design concept was quickly widely accepted: especially at the most cutting-edge, the most important "human-computer interaction" Of computer technology. The mouse and graphical interface (GUI) are regarded as the two most revolutionary and humanized industrial design cases in the microcomputer era. These two technologies were first applied to missile defense systems and military flight simulation systems. Their inventors were Douglas Carl Engelbart, who heads the Stanford University Center for Human Intelligence Enhancement Research, and Ivan Sutherland, a postdoctoral fellow in electrical engineering and computer science at the Massachusetts Institute of Technology.
Douglas Engelbart
Ivan Sutherland
Engelbart and Sutherland are loyal believers in Fitz's "human design" theory. This concept of "freedom in technology" quickly became popular through the self-organized "computer-made clubs" of Silicon Valley technicians. On the list of members of the club, there are many technical backbones of Xerox, IBM and other large companies, as well as founders and executives of more than 20 well-known Silicon Valley high-tech companies such as Apple, Sun and Cisco.
ALTO PC
In 1979, Xerox's Palo Alto Institute (PARC) first used a mouse and a "graphical user interface" (GUI) on an ALTO personal computer. The head of the institute, Larry Tesler, often receives complaints from programmers. On ALTO personal computers, even when editing a simple program or document, the operator must enter the "document input" and "document "Delete" frequently switches between the two operation modes, which is very troublesome and often causes errors. Therefore, Tesler proposed: "Instead of adapting humans to computers, why not make computers more human-friendly?" The solution is: the results of all input, modification and deletion by computer operators should be displayed directly on the computer screen in an intuitive way. come out.
In addition, Susan Kare, a computer programmer at PARC, has refined the important components of the graphical desktop of a personal computer based on human working habits in the real world. "Icons": such as "trash bins" and "files" "Clips" are distributed on the desktop of the computer in the form of small physical objects. With the mouse, users can click, open, close, or drag them to any location as they want, just as we do with physical folders and books on the desk in reality.
Steve Jobs and Apple Macintosh
In December 1979, PARC came with two hippie-dressed, casually dressed visitors: Apple Inc founder Steve Jobs, who was just three years old, and engineer Bill Atkinson. Tesler, who was present, recalled that they were shocked by the humanity and convenience of the ALTO PC. Later, many technical backbones of PARC Research Institute, such as Tyler and Carre, were dug to Apple. Tyler himself later became Apple's chief scientist and vice president. In 1984, he launched the revolutionary personal computer. "Mackintosh"-optimized mouse + keyboard, and iconic operation interface, has since become the standard configuration of personal computers. Jobs boasted that the computer has since become a technology product that individuals can own, as simple and easy to use as ordinary kitchen appliances. The "Fitz's Law" has also stepped out of Silicon Valley and quickly spread from consumer electronics to other fields.
Today, "user-friendly" has become our most basic and most important requirement for product design. Whether it is the multi-touch technology of the Apple iPhone, the Nintendo switch fitness ring with complex handle control replaced by body movement, the automatic shoelace binding system on the Nike adapt BB sneakers, or the simple integration of a Tesla S-type car The control screens have revealed a true meaning: the ultimate purpose of technological progress is to make human control of external devices into simulations of their own behavioral instincts, and to achieve rapid and seamless switching in them.