When it comes to designing software, the first step is getting familiar with the domain. The second step is modeling the domain into a more and more formal set of statements up to diagrams and code. To model the domain, Eric Evans suggested the use of something he called the “ubiquitous language”. In spite of the evocative name, it’s something as simple as a glossary of terms including verbs, names, adjectives, adverbs, form the pillars of a language being used in all written and spoken communications between all parties involved in the software project. The primary goal of the ubiquitous language is avoiding misunderstandings and assumptions on both ends—stakeholders and development teams. Put another way, the ubiquitous language aims at making any use of a given word or expression within the project absolutely crystal-clear and unambiguous. When that word or expression is used, therefore, there should be all around the absolute certainty that it was understood and in the right and expected way.
And now let me share a personal note to emphasize the vital role that a ubiquitous language plays in life and subsequently in software.
My wife had nose surgery a couple of months ago. In particular she had turbinectomy, namely the surgical reduction of her quite enlarged turbinate. When we discussed pros and cons, the doctor (aka, the development team) said clearly that it was a routine surgery with the hardest part of it coming in the following weeks once the patient had been sent back home. To illustrate possible complications, the doctor used the expression “nasal crusting” to be removed in a clinic or any sort of doctor’s office, in case of trouble. He also said that sometimes patients do so well that they never show up to remove nasal crusting.
We confused the term “crust” and“scab” and that was reasonable too as both usually happen when you have nose surgery. Now, crust refers to a mix of dried mucus, blood and dead tissue that altogether form a solid block as big as a small finger. A piece of crust is stuck inside the nose with barely any chance to get rid of it without a doctor. Scab is simpler matter as it’s a superficial cover on a wound of any type. You have scabs in the nose whenever you get significantly cold for example.
To make things worse, in Italian we use the same word for both crust and scab. To cut a long story short, my wife enjoyed two weeks of trouble until we called the doctor and he promptly removed the crust and explained us that crust is not the same as scab.
How many times did that happen to you software-wise? That’s just the ubiquitous language in action.
