The forgotten benefits of “low tech” user interfaces

Jonathan Kendler on 2022-05-17

Seemingly outmoded technologies sometimes hold the key to better user experiences.

I started my career as a user interface designer and human factors engineer 20 years ago. As a designer who focused on medical devices, most of the user interfaces I worked on back then were relatively “low tech”; user interfaces that convey information via LED lights or simple displays, like dot matrix or segmented LCD displays, and enable user interaction via physical controls such as push buttons, snap domes, and membrane switches.

Examples of low tech user interface components (from left to right): dot matrix display, segmented LCD display, membrane panel, and push button.

Over the first 10 years of my career, user interfaces that utilize more sophisticated technology, namely graphical user interfaces running on relatively high-resolution displays, became increasingly common among medical devices, as well as among consumer and industrial products. Today, sophisticated user interfaces running on high-resolution displays with capacitive multi touch capabilities have become so common that you’re likely using one to read this article. Such “high tech” user interfaces have become common enough that many product designers and engineers think of them as the default option when conceiving new products.

On many projects, I’ve also made the assumption that higher technology user interfaces enable better user experiences. But, a recent project reminded me that low-tech user interfaces can be superior to high-tech ones.

I recently led the design of a user interface for a home use medical device — a respiratory support device intended for use by elderly patients. As on many other projects, the product managers responsible for defining initial specifications assumed the product required a capacitive touchscreen display, of similar size and resolution to a contemporary smartphone. Given this assumption, I started designing an initial set of user interface concepts that made the most of the display by presenting large conspicuous values, providing animated instructions, and guiding the user through multi-screen workflows.

My client’s product development team was satisfied with the initial design concepts, so we planned to proceed and conduct an early usability test with prospective users. Until our plans were abruptly changed by the client’s vice president of engineering.

The VP was concerned that the capacitive touchscreen made the device too expensive. He challenged me to create a user interface using only low-tech components, such as switch buttons, push buttons, and 7 segment displays. I could work with any combination of such components, so long as they fit within his budget for the device’s cost. And, of course, this low-tech user interface would have to be as safe, usable, and appealing as the original touchscreen-based design.

At first, this seemed like an impossible challenge and perhaps another example of a company prioritizing profits over users’ needs. But, I decided to embrace the challenge and see what could be done to design a successful user interface using low-tech components.

Fast forward several months and we now have a user interface design that utilizes segmented LCDs and capacitive controls to deliver an intuitive and efficient user experience (as evidenced by usability tests with representative users).

The benefits of low tech user interfaces

In the process of exploring both low and high-tech options for this device’s user interface, I was reminded of some occasionally overlooked benefits that low-tech user interfaces provide, as well as some of the shortcomings they embody. Let’s start by looking at their relative strengths.

Tactile feedback

Touchscreens have become ubiquitous and many people now find them familiar and intuitive. But, for a lot of people, especially the elderly and those less experienced with high-tech products, touchscreens can seem intimidating. Conversely, physical controls can seem more familiar and comforting to these users, primarily because of the tactile feedback they provide.

Physical controls that are always visible can provide a clear sense of a device’s functionality at a glance. Depending on how the controls are organized and differentiated by size or shape, users might also be able to distinguish between and access the controls without needing to look at the user interface (which can be helpful at night or in situations where the user’s attention might be elsewhere). And when a user actuates a physical control, they typically receive some form of physical feedback (e.g., a button detent or click) that confirms a successful actuation.

Users of continuous positive airway pressure (CPAP) machines might wish to start, stop, or adjust their therapy at night without having to look at the device. Physical controls enable them to do so, while a touchscreen might not. (Photo courtesy of https://www.blf.org.uk/support-for-you/obstructive-sleep-apnoea-osa/cpap-machines)

At some point, touchscreens that provide haptic feedback will become more common, but for now, tactile feedback remains a key benefit of many tech user interfaces.

Lower cost and lower price

As I mentioned earlier, my client’s initial motivation for exploring low-tech user interface solutions for their respiratory device was a financial one. Low tech user interfaces are usually cheaper to manufacture than high tech ones. While this might seem to only benefit the company’s profits, it actually can be quite beneficial to users as well.

In the case of the respiratory device I described, a lower cost user interface enables the product’s final price to be drastically lower than a higher tech user interface would have allowed. Importantly, a lower price means that health insurance companies would cover the costs associated with the device’s use, which in turn means that more patients would benefit from the therapy it provides. In such cases, a higher tech but more expensive solution would result in fewer patients benefiting from its therapy.

Notably, lower tech user interfaces often cost less to develop because they require simpler software tooling and logic than higher tech user interfaces. Which brings us to the next benefit.

Ease of software development

When developing a budget for a new product, many manufacturers tend to focus on the costs of the physical components required to build the product’s user interface (e.g., the cost of a high-resolution color touchscreen vs the cost of a pixel LCD). But, behind these costs, hide additional costs associated with the development of software that drives the product’s user interface.

In general, higher-tech user interfaces require a more complex and more expensive investment in software development. At a minimum, developing a high-tech user interface for an embedded device involves costs of licenses for user interface frameworks (such as QT), design and implementation of multiple screens, localization into multiple languages, and more involved quality control procedures. By contrast, lower tech user interfaces tend to require simpler software development efforts (or even a lack of software development) by virtue of the simpler logic required to interpret user interactions with physical controls and present information using LEDs or basic displays.

Reliability

Touchscreen user interfaces and high-resolution displays certainly have their perks, but most long-term users of mobile devices have likely experienced some of their shortcomings. Broken screens, “dead pixels”, and significantly lowered battery lives are all more likely to occur with more sophisticated user interfaces. In safety-critical products, such as medical devices or industrial equipment, such reliability issues can be a significant drawback.

“Dead pixels” can obscure important information in user interfaces or make a user interface unusable. (Photo courtesy of https://www.reddit.com/r/mildlyinteresting/comments/5sdqk7/the_dead_pixels_on_my_screen_are_spreading_out/)

On the other hand, simpler user interface components, many of which have been around for a long time, have been thoroughly stress tested by their manufacturers and the many products that have utilized them over many years. Their failure modes are more familiar and predictable than those of high-tech displays, thereby enabling product developers to better account for their failure modes. Of course, they can also be vulnerable to wear over time (such as silk-screened button labels becoming faint after extended use), but in general, they provide more reliability than higher tech user interfaces.

More constraining

The final benefit of lower tech user interfaces doesn’t directly help the product manufacturer or the end user. Rather, it helps the user interface designer in a somewhat counterintuitive manner.

Despite their lower technical complexity, lower tech user interfaces are difficult to design. Specifically, making an intuitive, efficient, and error-resistant user interface that uses only low-tech components, is a challenge that will likely require significant design effort, iteration, and designer ingenuity.

That doesn’t sound like a benefit. But, the constraints that lower-tech user interfaces place on designers can actually help them focus on the aspects of use that are most critical to the user experience. High-resolution touchscreen displays give designers an almost infinite “canvas” in which to work, leaving them free to add as many screens, icons, prompts as they wish. On the other hand, lower tech user interfaces give designers strict constraints driven by factors beyond the user interface designer’s control (e.g., the physical size of the device, the budget allocated for the user interface components, etc.).

These constraints push designers to “sculpt rather than draw” — that is, to optimize a user interface by eliminating elements instead of adding them. When designers embrace the constraints created by lower-tech user interfaces, they can arrive at solutions that are simpler than they might have originally imagined possible.

This has been my experience with the recently designed home-use medical device and with other low-tech user interfaces I’ve designed in the past. One of the “simplest” products I ever worked on was a neuromodulation device that provides therapy to patients with urinary incontinence. Users operate the device by powering it on, adjusting the stimulation level, and starting, pausing, or stopping therapy. That sounds straightforward, but presenting all the associated information in a 2 x 1/2 inch monochrome segmented LCD display is not. My design team created around 30 different design concepts before arriving at a design that, in retrospect, looks like an obvious and straightforward solution.

Left: A neuromodulation device designed in the early aughts. Right: A sampling of the 30 different user interface concepts my team created.

Possible low points of low tech user interfaces

Low tech user interfaces are not the answer for every product. In the following cases, higher-tech user interface solutions are likely to be more effective.

Lack of adaptability

Many products evolve over time. New features are added via software updates. The user interface is translated into additional languages that weren’t considered during the initial design. The user experience is adjusted based on new findings regarding user needs and preferences.

When you expect a product to evolve in the near or far future, low-tech user interfaces are likely to introduce challenges. For example, you might run out of space on a segmented display when adding icons to represent new system states. Or, you might not have enough space to add a new control. Or, your previously wordless user interface now requires the addition of a couple words that have to be translated into different languages, requiring you to create unique membrane overlays for every country in which the product is sold.

More difficult to localize

One of the benefits of software-driven graphical user interfaces that run on more sophisticated displays is that they can more easily accommodate localization and internationalization than lower tech user interfaces. When a user interface can get away with only icons in place of words, a low-tech user interface can work particularly well. But, in cases where you need more language to convey instructions, warnings, or more complex content, a higher tech user interface is superior.

Negative user perception

During the recent home device project I mentioned earlier, one of the biggest supporters of a touchscreen-based solution was the team’s marketing specialist. Their concern was that users have become accustomed to high-resolution touchscreen displays and would consider any alternative as archaic.

This is an understandable concern. Many consumers judge product qualities based on superficial impressions and studies have shown that these impressions can cause users to perceive a product as less usable than it actually is. If a product’s success is dependent on customers perceiving it as a cutting-edge solution, there might be a valid business rationale for utilizing a high-tech user interface.

Having said that, low-tech user interfaces don’t have to look low tech. Industrial designers can find creative ways to dress up a low-tech solution so that its aesthetics are contemporary and appealing. Newer low tech solutions (yes, that’s a bit of an oxymoron) like ultra wide view LCDs enable manufacturers to implement conventional segmented LCD technologies in a manner that makes them appear sharper and cleaner than high-end OLED displays.

Consumer appliance manufacturers, such as Whirlpool and Panasonic, incorporate low tech user interfaces into effective industrial design to optimize aesthetic appeal (Photos courtesy of Red Dot Design Awards).

Give low tech a chance

Low tech user interfaces are not a solution for every product. But, if you’re a product or user interface designer, I encourage you to consider low-tech solutions when working on new products. If nothing else, treat it as a thought exercise or design challenge: how can you turn your multi-screen touch-based design into a simplified user interface that relies on nothing more than icons, LEDs, and a segmented display? What is the smallest number of user interface elements that you can use and still produce an intuitive and engaging user experience? If you embrace the challenge, you might be surprised by the designs you create.