I came across this the other day. It is a meme that has been making its way around the net for the past couple of years and purports to show how the mind is able to make sense out of jumbled words as long as the first and last letters are correct. Here is an excerpt  from this site: 

Regardless of whether the post accurately represents the science, I think it touches on something about human cognition that is critical in the world of requirements – context is key. In the excerpt above, it was an understanding of the context that allowed you to parse “cluod” in the first sentence as “could” rather than “cloud.”

Where this subject falls into the realm of requirements is as it pertains to use cases. Conversations between business users and developers will too often have a low signal to noise ratio. Each group has a different lens through which they view the world, a difference in perception that can get in the way of understanding those who do not share the same vantage point. Use cases, when done right, provide the necessary context within which business users and developers can effectively discuss a system under development. By distilling a problem to its essence and stripping away jargon and other unclear language, well-written use cases can act as the common reference point needed for development of a shared understanding among a diverse population of stakeholders.

Of course, the creation of use cases most assuredly doesn’t mean that you can randomly start swapping letters in your requirements documents. Their presence will give you a significant advantage however when downstream consumers of the specifications are able to place your intent within the proper business context. Although they are certainly not the panacea that some may claim, the context that use cases provide makes them a powerful weapon within the overall requirements arsenal nonetheless.