What Is Usability

• Have you ever bought a new home appliance like a TV or an air-condition and it was almost impossible to figure out how to make it work?
• Have you ever entered at a website in order to buy a product or to search for a specific information, only to find that you could not understand where were you and where did you have to go?
• Have you ever used an application in your pc or Mac that made your life difficult by hiding functional buttons or by naming them in a way that was not making any sense?

Definition

There are many definitions of usability, as it is a term that interacts with many other fields such as I.T. or Psychology. Despite that, there have been some efforts to find a common ground and thus a common definition. For example according to the International usability standard, ISO 9241-11, usability is related to:

The effectiveness, efficiency and satisfaction with which specified users achieve specified goals in particular environments.

Another definition by Jacob Nielsen, a Usability Guru and one of the first that emphasized on the importance of usability:

Usability is 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.

In essence usability is something that tells us how easy and enjoyable it is (or it is not) to complete a task using a particular interface (be it a website or your microwave). But when did it started to become a major factor in application and web development?

History

Usability as we have seen is about making things working more easily and effectively. With that in mind, we can say that this term has been around for as long as humans exist. After all, cavemen were constantly refining their tools in order to hunt and farm better. But it is not up until the previous 30 to 40 years that we started to apply a scientific approach with experiments, laws and theories to this matter.

The aviation industry was the first that conducted usability tests and started to form the usability science as we know it today. It is true that a plane is expensive to build and it causes a big amount of damage in case it falls, not to mention that it is useless after a crash. Something had to be done in order to increase the easiness of use and to reduce the human errors and so by the end of the World War II, the first usability centers in Brooks Air force Base in Texas and Wright field in Ohio were a reality. After that, it was just a matter of a few years before the “secrets” of usability and usability testing started to be applied for commercial and business purposes. Indeed, Henry Dreyfuss, an American industrial designer, conducted some tests around 1940 in order to find the proper design for the rooms in two ocean liners. From an excerpt from Wikipedia we see that:

He built eight prototype staterooms and installed them in a warehouse. He then brought in a series of travelers to “live” in the rooms for a short time, bringing with them all items they would normally take when cruising. His people were able to discover over time, for example, if there was space for large steamer trunks, if light switches needed to be added beside the beds to prevent injury, etc., before hundreds of state rooms had been built into the ship.

Until this moment the word “usability” didn’t even exist (at least with the way we use it today). From the 1960′s to the 1980′s where the first computers were created and the science of I.T. was being formed, there was a term that can be considered as the “father” of usability, Human Computer Interaction (HCI). And that is because for the first time computer, behavioral, cognitive and social sciences were starting to mix and cooperate. It is a period were GUI’s (Graphical User Interfaces) appeared and various models and theories were created that eventually would form later the science of usability and user experience.

Then, in 1984 Don Norman wrote “User-Centered System Design”, a book that made the engineers and programmers to start thinking about the end user. Around the same time, Brenda Laurel’s “Computers as Theatre” coined the term User Experience and by the end of 1980, John Whiteside at Digital Equipment Corporation and John Bennett at IBM, published a number of papers and topics on the subject of usability engineering. This is considered by many to be the “official” start of the science of usability. But the moment where usability became what it is today was in 1993, when Jacob Nielsen published “Usability Engineering”. This is when engineers and programmers realized that they had more to gain than to lose if they made more user-friendly interfaces and applications.

Importance

And why is usability important? According to Jacob Nielsen:

On the Web, usability is a necessary condition for survival. If a website is difficult to use, people leave. If the homepage fails to clearly state what a company offers and what users can do on the site, people leave. If users get lost on a website, they leave. If a website’s information is hard to read or doesn’t answer users’ key questions, they leave. Note a pattern here? There’s no such thing as a user reading a website manual or otherwise spending much time trying to figure out an interface. There are plenty of other websites available; leaving is the first line of defense when users encounter a difficulty.

An easy and usable website/interface gives to the users the opportunity to achieve their goals effectively and efficiently, which will result in increased satisfaction. Let’s not forget that only satisfied customers come again to buy from us while at the same time they spread the word that we are a trustworthy and legitimate company. Moreover, many studies have shown that improving usability results in more sales and increased user productivity (once again, see one of Nielsen’s pioneering studies here).

This was a brief introduction to the world of usability, a huge subject with many opinions and theories that come with it. But what is usability to you? Do you have a specific definition about it? Share your thoughts and comments below.