November 22, 2013 -
Usability and functionality should be a primary concern for designers and manufacturers of biometric systems. Though such systems typically are deployed for security applications, they should still provide an exemplary service experience that quickly meets the basic needs of the user, without fuss or bother.
Most would attest that the air travel experience is anything but an exemplary one. Travelers in the high-security, post-911 era have to run a high-paced gantlet of airline flight check-in, along with baggage drop-off, security clearance and passport control. Any systems that ease such a stressful process are welcomed.
Biometrics have the capacity to both simplify and speed the traveler experience, but often usability is not always a primary consideration in security system design. Biometrics such as fingerprint and iris recognition are often used to authenticate high-frequency and low-risk travelers by national border security services. These systems however are mainly designed for durability because of the high number of users potentially utilizing the systems. This can unfortunately lead to the design of systems where “usability” is not a primary focus.
Jakob Nielsen, a noted technology design expert, defines usability as a “quality attribute” that assesses how easy user interfaces are to use. The word “usability” also refers to methods for improving ease-of-use during the design process. Obviously, if biometric security systems at the border are not easy to use, traveler aggravation will result, due to misunderstandings concerning how to actually use the system, which will lead inevitably to transit delays.
For this reason, designers of biometric border security kiosk systems should place at the forefront a number of general design principles to guide the development of future products. Here are some principles that Nielsen has suggested, which we have adapted to address biometric security system usability.
The first principle that biometric product manufacturers should consider is designing a system that speaks the users’ language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Systems should be designed to follow real-world conventions, making information appear in a natural and logical order. Ultimately, users should not have to wonder whether different words, situations, or actions mean the same thing. The kiosk system should have easy to follow user conventions and instructions.
To further enhance usability, error messaging needs to be clear and concise. Error messages should be expressed in plain language, utilizing no codes, and precisely indicate the problem, along with suggesting a constructive and authoritative solution. Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to an action.
System designers should also work towards minimizing a user’s memory load by making objects, actions, and options visible. The user should not have to remember information from one part of the dialogue to another. Instructions for use of the system should be visible or easily retrievable whenever appropriate. Dialogues should also not contain information which is irrelevant or rarely needed. Designers should recognize that every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.
Even though it is better if the system can be used without documentation, it may be necessary to provide help and documentation. Any such information should be easy to find, focused on the user’s task, list concrete steps to be carried out, and not be too large or difficult or time consuming to understand.
Systems ultimately must be designed to be used without human assistance. All too often, biometric kiosk and other biometric-based systems require the assistance of border security staff, which is an indication of system design failure. Also, quite often, many of these identity authentication systems are simply offline and not available. Governments should remember that unavailability of such systems completely undermine policies that promote fast and secure border movement in an age of liberalized trade and travel.