Computer-Centered versus User-Centered Design
Within the next few years, most physicians in this country will have converted from paper-based charting to electronic health record (EHR) technology. This is an unprecedented technological change in healthcare delivery. Whether this technological transformation succeeds will in large part depend on the design of the EHR software itself.
As a physician in clinical practice, my day-to-day care of patients depends in large part on how easy or difficult it is to interact with my EHR. Like many of my colleagues, I find that while my EHR provides all the necessary functionality, using it requires too much cognitive effort. In other words, the EHR design is computer-centered instead of being user-centered.
What’s the difference between computer-centered and user-centered design? Let me give an example.
Imagine that you and your very young son have recently started playing tic-tac-toe against each other on two networked computers. Your son thinks he should be winning more games, so he proposes a change, not in the rules, but in your screen view, in order to make the odds more even.
While his screen view of the tic-tac-toe grid will remain the same, your screen view will no longer be the standard three-by-three grid, but rather will be a single row of nine boxes.
He enlists his older sister, who is great with computers, to program your new user interface. Each of you can only see your own screen.
The first three boxes in your row correspond to the three boxes in the top row in his grid, the next three boxes in your row correspond to the three boxes in the middle row of his grid, and the last three boxes in your row correspond to the three boxes in the bottom row of his grid.
So, for a particular game, your respective screen views would be as follows:
All of the sudden, you find that you’re working pretty hard just to play tic-tac-toe. You’re working hard because you can no longer ‘see’ the problem.
First you have to mentally reconstruct the normal three-by-three tic-tac-toe grid, then mentally segment your row of nine boxes into three groups of three, and then transpose each segment back onto the appropriate part of the tic-tac-toe grid that you are keeping in your head. (Alternatively, you might decide to solve the problem using a different strategy, but that would still require cognitive effort on your part.)
With a lot of effort, you’re able to stay pretty even with your son, but then your daughter introduces a second challenge — a two-second time limit for each move. At this point, your son starts winning a lot more games than you, restoring family harmony.
What is interesting about this example is that, from a logical perspective, the two screen views contain exactly the same amount of information. And, in fact, if a computer program were using an algebraic algorithm to play tic-tac-toe against you, the screen view would be immaterial.
But for humans, it is clear that the grid view works better. It works because we can literally ‘see’ the solution.
If we see a tic-tac-toe grid, we can visually superimpose horizontal, vertical, or diagonal lines at will. If we are faced with the game position below, we don’t have to compute the slope of the line passing through the two Xs or solve an equation to know whether that line would also pass through the square on the bottom right.
In other words, the human brain is an extremely powerful computer, but one that evolved to help us survive in the physical world by making sense of our spatial environment. Our brain is almost always better at solving problems visually than by using formal logical or mathematical operations.
Donald Norman, a cognitive scientist and pioneer in applying human cognition to design, has written extensively on this topic. In Things that Make Us Smart, he devotes a chapter to why certain design variants are easier for humans than others, even if the variants are formally identical. He includes one diabolical example which turns tic-tac-toe into a variant of Sudoku.
Humans enjoy solving mental games and puzzles for fun, which is why we invent things like Sudoku, but we don’t enjoy them at all when they interfere with complex tasks. Physicians need to be able to devote their full cognitive attention to patients in order to help solve their very real health puzzles.
As physicians, we need user-centered EHR designs that take advantage of our innate visual and spatial perceptual abilities and stay in the background, instead of competing with patients for our finite cognitive resources. Far too many EHR designs force us to play linear tic-tac-toe.
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Rick Weinhaus MD practices clinical ophthalmology in the Boston area. He trained at Harvard Medical School, The Massachusetts Eye and Ear Infirmary, and the Neuroscience Unit of the Schepens Eye Research Institute. He writes on how to design simple, powerful, elegant user interfaces for electronic health records (EHRs) by applying our understanding of human perception and cognition. He welcomes your comments and thoughts on this post and on EHR usability issues.