As for the definition / your interpretation though, you’re quite correct, that definition is widely accepted by many people, myself included. However in your aim, question and metaphor you state that usability is just about goals, ignoring the satisfaction part. For example -

” Usability can be modeled as the question “Can the user accomplish their goal?” whilst user experience can be phrased as “Did theuser have as delightful an experience as possible?””

That’s not correct. According to the definition, usability covers both of these things. Your distinction is wrong. Usability is what you’ve described as UX, ie. Something real and testable that includes perception of experience. In reality all that UX is is a confusing umbrella term for many different job titles.

That is my point.

I seriously doubt that you have read or understood this post.

Firstly let us start with definition – I quoted ISO’s definition of usability which, apart from being issued by ISO, has been cited by numerous Usability and UX professionals.

Let us just assume everyone is wrong. Still, it says: “effectiveness, efficiency and satisfaction with which specified users achieve specified goals in particular environments” (ISO 9241-11). Notice the word satisfaction. So, I ask myself, why did you write “Your interpretation and the interpretation in the diagram both miss out the ‘satisfaction’ part of the definition”? As for the diagram, it is there NOT to show what usability is but to show the relationship between usability and user experience, which, mind you, is the subject of this post.

You say that UX is not the domain of designers BUT, I wrote that “user experience requires the collective and seamless effort of employees from various departments including engineering, marketing, graphical and industrial design and interface design”. I never said that UX is solely the domain of designers. So, what is your point here?

@Kalle,

Strange definitions? Really? If you never encountered the ISO definition of usability, well, that is what I consider as being strange.

Moreover, if being entirely part of something (usability part of ux) is not enough of an overlap, then I really can’t imagine what “much greater” overlap can there be!

However, the article above is using strange definitions of usability and UX. Usability DOES include satisfaction, look and feel as well. It is just that in UX, emotions and feelings towards the overall experience tends to be more in focus than for usability.

There is a much greater overlap between the two concepts than the article describes.

Here is the definition section from working draft of ISO 9241-11:

“For the purposes of this part of ISO 9241, the following definitions apply:

3.1. usability: The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.

3.2. quality of a work system in use: The extent to which specified goals can be achieved with effectiveness, efficiency and satisfaction in a specified work system.

Note: The difference between usability and the quality of a work system in use is a matter of focus. When usability is evaluated, the focus is on improving a product while the other components of the work system (user, task, equipment, and environment) are treated as given. When the quality of a work system in use is evaluated any component may be subject to modification or improvement.

3.3. effectiveness: The accuracy and completeness with which users achieve specified goals.

3.4. efficiency: The resources expended in relation to the accuracy and completeness with which users achieve goals.

3.5. satisfaction: The comfort and acceptability of use.

3.6. context of use: The users, goals, tasks, equipment (hardware, software and materials), and the physical and social environments in which a product is used.

3.7. work system: A system, consisting of users, equipment, tasks and a physical and social environment, for the purpose of achieving particular goals.

Note: The context of use consists of the goals of the work system and those components of the work system which are treated as given when specifying or measuring usability.

3.8. user: The person who interacts with the product.

3.9. goal: An intended objective.

3.10. task: The activities undertaken to achieve a goal.

3.10. product: The part of the equipment (hardware, software and materials) for which usability is to be specified or evaluated.”

Here is the full definition from ISO 9241-210

“User Experience:
A person’s perceptions and responses that result from the use or anticipated use of a product, system or service

Note 1: user experience includes all the user’s emotions, beliefs, preferences, perceptions, physical and psychological responses, behaviours and accomplishments.

Note 2: user experience is a consequence of the presentation, functionality, system performance, interactive behaviour, and assistive capabilities of the interactive system. It is also a consequence of the user’s prior experiences, attitudes, skills and
personality. People can have

Note 3: usability, when interpreted from the perspective of the users’ personal goals, can include the kind of perceptual and emotional aspects typically associated with user experience. Usability criteria can be used to assess aspects of user experience.”

So I see the difference between usability and user experience that usability is oriented on the process of usage while user experience also includes pre- and post-usage.

If you are a user researcher then you need skills in planning, recruiting, scripting, facilitating, data analysis, persona creation.

IA it’s things like domain modelling and card sorting, coming up with url structures, cross-linking, entity relationships and data schemas.

Interaction design it’s persona use, flows, wireframing, specifications, functional prototyping.

Visual design – moodboards, scamps, polished PSDs.

All of these professions contribute towards both usability and UX.

Usability = a goal to work towards
UX = an umbrella term to cover all points at which a user interacts with a product

I’d contest that neither of those are professions. There are many different professions that contribute to both usability and UX.