The history of interface design is typically told in the mode of art history. It is a story of visual ideas: grids, buttons, swipes, information hierarchies.

In many ways we can compare it to the history of painting. In the medieval period, subjects were arranged on the page in a seemingly haphazard fashion. Two identical human figures might be side by side yet different sizes. Space was irregular and symbolism was the ordering principle. Then in the Renaissance a transformation took place where the painting became structured using the rules of perspective. One could learn about the world by measuring the properties of objects in such paintings–their positions and sizes.

As Lewis Mumford showed in his classic text Technics and Civilization, these changes in visual form of paintings actually correspond to massive changes in the way space as a whole was organized. At the same time that painters drew perspective lines, cartographers drew lines of latitude and longitude. In the first chapter he explores the way that a new conception of measurable space led to new behavior:

No longer was in necessary for the navigator to hug the shore line: he could launch out into the unknown, set his course toward an arbitrary point, and return approximately to the place of departure.

Mumford, Technics & Civilization, p21

Changes in space change the way we move, and most importantly, change the way we move together. New kinds of activity become possible.

This raises the question: what conceptual changes are encoded in the visual language of user interfaces? How have changes in pixels corresponded to changes in what counts as measurable and to what kinds of coordinated, planned activity are possible?

If I may take a first pass at the question it seems to me that the big change in the last 20 years has been the introduction of user analytics. Before when a product left the factor the only thing that manufacturers could do was plan the next product. But now companies can measure user behavior in real time. The result is that products can optimize their design in real time to better reach their goals. Companies can now set course for an arbitrary target, for examples boosting the typical “engagement” with a product from 3 weeks to 6 weeks, and be confident that they will be able to change the design of their product to make this a reality.

This suggests that simplified user interfaces are best not read in aesthetic terms. It is true that the style and arrangement of pixels on the screen does represent the triumph of Josef Mueller Brockman and the originators of minimalist typogaphic systems. Yet there is another layer here that needs to be explored. Just as psychologists designed simplified spatial environments–mazes–to better measure the learning and adaptation taking place inside the minds of rodents, simple user interface designs allow companies to conduct experiments en masse on their users.