Edge case

The term edge case is used to describe an atypical or less commonly encountered use case or user for a product or service. The traditional approach implies that the edge cases are more difficult to solve and serve fewer people and therefore are to be avoided. The long-held belief is that organizations can serve most of their addressable market without solving these tougher challenges.

As a result of this traditional approach, edge cases would often not be accommodated by a  product or service, making it more difficult or even unusable in these cases.

For example, for a website, an edge case could be considered someone who would exclusively view the site in high contrast mode due to an uncommon vision impairment. However, this kind of consideration would be a common benefit for many users, not just those with a particular kind of vision impairment. Dismissing such a benefit because it may impact only a small percentage of users would be a detriment to the overall product and could require a significant effort to accommodate in the future.

As such, we know now that solving for the more difficult use cases first—particular when they lead to more ways to access content and engage with an organization—leads to much richer products or services that ultimately require less time and resources to capture market share.