What is Usability

The purpose of technology is to empower humans, our purpose is to be able to understand it and usability stands between these two concepts.

Usability testing is not just a collection of different opinions and research, instead it involves watching people trying to use the product to accomplish their tasks, at the same time it measures the product’s capacity in accomplishing its intended purpose.  Basically you have the chance to experience a “live feedback” from users. The word “usability” also refers to methods for improving and measuring the ease-of-use during the design process. Usability Evaluation focuses on how well users can learn and use a product to achieve their goals. It also refers to how satisfied users are with that process. In short, Usability is the relationship between the program and its audiences.

In my opinion usability is a wide definition which is hard to narrow down on a one solid statement, here are some definitions of usability merged together:

According to ISO 9241 definition, Usability means:    

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

Effectiveness: the accuracy and completeness with which specified users can achieve specified goals in particular environments.

Efficiency: the resources expended in relation to the accuracy and completeness of goals achieved.

Satisfaction: the comfort and acceptability of the work system to its users and other people affected by its use.

Another definition:

Intuitive design: a nearly effortless understanding of the architecture and navigation of the site

Ease of learning: how fast a user who has never seen the user interface before can accomplish basic tasks

Efficiency of use: How fast an experienced user can accomplish tasks

Memorability: after visiting the site, if a user can remember enough to use it effectively in future visits

 Error frequency and severity: how often users make errors while using the system, how serious the errors are, and how users recover from the errors

Subjective satisfaction: If the user likes using the system

‘A Practical Guide to Usability Testing’ (rev. ed., Dumas and Redish, 1999). Dumas and Redish use four points to their definition:

1. Usability means focusing on users

2. People use products to be productive

3. Users are busy people trying to accomplish tasks

4. Users decide when a product is easy to use

What usability is not

Out of the scope                                                                                                                         

Thinking that usability requires knowledge of psychology or visual arts and it is outside the scope of what programmers do it is false. Also thinking that there should be only one person who is in completely in charge of usability testing it is false. Of course there will always be a role for usability specialists, but basic competence in usability engineering should be part of every programmer’s craft.

A finishing touch   

Usability testing should not be treated as a “finishing touch” after the design phase. After conducting a usability test, we can never assume that that software is now usable. Usability is a process that changes over time, what was considered to be usable some time ago may not be considered usable now. So to ensure good usability, we need to test in an iterative way throughout the design and development process, always involving users.

Spot the differences

Usability vs UX  

UX is the overall experience of a person using a product such as a website or computer application, especially in terms of how easy or pleasing it is to use, it is more about users emotional connection and experience using the product.

The User Experience Honeycomb

Usability is one of the components that influence the overall User Experience. Is the ability to do something intuitively and easily. So,just because something is easy to use, does not necessarily mean that is a good user experience.

Usability vs Utility

Definition of Utility = whether it provides the features you need.

Definition of Usability = how easy & pleasant these features are to use.

Definition of Useful = usability + utility

Usability vs Functionality                                                                                                

Functionality is the ability of an interface or device to perform according to a specifically defined set of parameters.Functional testing requires the mindset of “CAN I do what I need to do, does this product work?” whereas usability has the mindset of “HOW can I do what I need to do, does this make sense?”

So, this is a wrap for this weeks post where the main goal was to build up an understanding of usability testing Feel free to leave any comments, I’d love to know your opinion and discuss more about usability.

See you next week 🙂






4 thoughts on “What is Usability

  1. That’s a very good summary of usability. You are right; there are several definitions to usability. As you mention, some prefer the definition of usability to be a combination of “learnability” (how well you can figure out the program the first time you use it) and “memorability” (how well you can remember how to use the program, the next time you use it) with other factors.

    Redish & Dumas’s four points about users is a good definition, and one I often come back to. I usually summarize these points as “Users are real people trying to do real tasks, and they want to do them in a reasonable amount of time.” If a system doesn’t let real people do real tasks, it’s not useful. And if it takes forever to do something in the software, that’s not useful either. It’s all about the users (“Users decide when a product is easy to use”).

    I like that you highlighted how UX is more about users emotional connection and experience using the product. UX is different from usability, although you’ll often see them going together. In most cases, a program with good user experience also has good usability, and a program with poor user experience has poor usability.

    But it’s not always the case. These “edge cases” are interesting to me. For example, some games are a lot of fun, but very difficult to learn. For me, the ‘Hedgewars’ game (http://www.hedgewars.org/) is loads of fun, but I have a very very hard time figuring out the controls. The controls don’t make sense, and the time limit on turns makes this very frustrating. Once I learn the controls, I always have fun. But the other problem is the controls aren’t memorable. If I only play the game on the weekends, I don’t remember the next weekend how to play the game, and I have to go through the entire frustrating experience of learning the controls. Poor usability (learnability & memorability) but good UX.

    You can also have a program that is very easy to use, easy to figure out, obvious enough that you remember how to use it again the next time you use it. But the weird fonts and dark colors might be very off-putting. I tried a file manager like this once, and the developer decided it would be “cool” to put everything in ALL UPPERCASE. Every pop-up window was like the program was SHOUTING AT ME. The program was dead simple to figure out, really easy to use. But I just didn’t like using it. Good usability, poor user experience.

    But those are edge cases.

    Liked by 2 people

  2. Hey Renata,

    I really like the inclusion of “what usability is not” in your post for this week. The points you brought up seem really crucial. It’s good to inform/remind developers that usability testing does not necessitate a specialist, spending lots of money, or sidetracking any other aspect of development. I think a lot of open source software would really benefit from more frequent usability testing. Great post!

    Liked by 1 person

  3. Hi Renata,

    thanks for the blog post – its awesome to see people taking care of the users’ needs within the free software environment 🙂

    With regard to Jim’s edge-case ‘Hedgewars’ – my usual description is that its “intended use” is rather to “stimulate” but to provide a certain set of features to accomplish a rational goal. If one designs games, then you need to get the (non)usability just right … that helps to achieve a flow effect where the user is neither bored nor overstrained. Instead, just right for the intended target group. The motivation of people to cope with this “non-usability” is e.g. “mastering” it.

    The same effect is sometimes also visible for software tools … even if a tool is “bad” from a ease-of-use point-of-view, and even if there are better alternatives, some people might love it. Because they mastered using it, and others did not (yet).


    Liked by 1 person

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