Expert Systems – When complexity is necessary


When we think about usability and user centered design we’re typically thinking about the first time user, or the ease of use and enjoyment for a current user with a digital interface. Simplicity, not complexity is usually the goal as Don Norman would say. Though Don Norman would argue on his website that the concept of simplicity is over rated because of the public’s desire for new features. In the market ammount of features tend to sell. Yet as users and designers, we desire crisp easy to use interfaces for the technologies we use every day. Yet some interfaces that are used every day such as a pilot’s cockpit and the Bloomberg Terminal appear to be extremely complex from an outsider’s point of view. These systems are complex for a reason and the users that master them could be considered experts. Why so complex? In the case of a pilot’s cockpit, one reason could be to prevent any average Joe from walking into a cockpit and operating an expensive piece of machinery. Expert systems can’t be totally overhauled to make them more “user friendly”, but the learning curve can be flattened.

In the case of a pilot’s cockpit, all of the controls are presented in front of the pilot. This allows the pilot to see every button that’s pressed, every level on every gauge that corresponds to every knob. This gives the pilot full control at all times of the aircraft, while at the same time promoting situational awareness. The controls are adjacent in space, eliminating the need for navigation if the pilot knows the layout of the controls well enough. Losing that complete control can result in fatal consequences.

Bloomberg has a UX department that employs the iterative design process, but with different goals. Financial data vendor Bloomberg, creators of the Bloomberg terminal, is one of the most popular computer systems for real time market analysis and real time trading with over 300,000 subscribers worldwide.

For Bloombergs UX team, they are aware that the interface they are constantly trying to improve, can’t deviate too much far from what the expert is comfortable with. On the UX page on their website, they acknowledge that there will always be a learning curve, because it’s an expert tool. Thier UX team says their goal is to flatten that learning curve. The power of the system to users is in its complexity, allowing users to operate potentially four independent command lines on four different screens.


The terminals usability comes after the user masters the shortcuts. The keyboard itself is based of the normal qwarty keyboard, but the function keys are given specific functions and color coded, to allow users to make color associations. According to Michael Bloomberg in his autobiography the keyboard was designed for traders who had no prior computer experience and it was made with desk space in mind as well.

These expert systems are catered to the experts that use them. So big overhauls are hard to pull off. In the case of the Bloomberg terminal many people have been using either the current GUI or the just keyboard for many years so it would be unreasonable to ask those experts to relearn shortcuts. In 2007 design firm IDEO even proposed a redesign of the terminals graphical interface, but Bloomberg responded saying they weren’t looking to redesign the interface anytime soon. But why not do a complete overhaul to eliminate the sharp learning curve and to make it more user friendly for everyone. Dominique Leca from UX magazine would argue that the users of the Bloomberg terminal like the fact that it’s an expert system that’s learned, and they get some sort of satisfaction using a system that is viewed as very complex from the outside. While a this is cynical view of it for sure, there is some truth in taking pride in mastering a complex system.

For a pilot’s cockpit, simplifying the complex layout of the controls could be detrimental to the safety of the passengers and the pilot. From the pilot’s point of view, the fact that they have to so much in front of them to keep track of while in flight prevents them from losing focus on the task.

While these systems betray emerging UX principles of eliminating clutter in the interface, the end users satisfaction with the system is present. Instead of UX professionals testing for ease of use for a first time user, these professionals cater to the experts that have taken the time to learn the system. It all may just be as simple as trading finances, a flying an airplane are complex tasks and they require complex systems to achieve the tasks.