I’m often asked what definition of usability we use at GDS.
My short answer is that a government service is usable if the people who need it can use it to get the right outcome for them.
It’s point 12 in the Digital Service Standard - make sure users succeed first time.
And it’s one of the 3 primary measures of a service we’re using for the Cross-Government Service Data alpha - the number of transactions ending with the user’s intended outcome.
But some of the people who ask this question are really asking whether we use the definition of usability given in international standard ISO 9241:
The extent to which a system, product or service can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.
My answer for them is a bit longer.
Effectiveness takes priority
In ISO 9241 terms, we care most about effectiveness - can people use the service to get the right outcome for them?
People come to government to do important things. If they can’t get them done, it can cause significant problems in some aspect of their life or work.
And those problems drive up government costs and stop policies achieving their intent.
We do care about efficiency. If part of a service is used by businesses or public servants several times a day, then designing for efficiency is very important. But in most cases we will sacrifice some efficiency to make a service more effective for more people.
And we do care about satisfaction. But we know that for most government services, how users’ feel about a service is very closely tied to whether they can use it effectively to get the right outcome for them.
To auto-tab, or not to auto-tab
An example of this is ‘auto-tabbing’. You’ll see this when you enter a value like a date, a bank sort code, or a license number, and the system moves automatically from one box to the next.
Forms on GOV.UK don’t auto-tab.
In usability testing, some participants notice this. And they grumble about it. But they quickly enter the information they need to, and move on.
At the moment, we don’t know a way to implement auto-tabbing that works for all our users.
And if auto-tabbing stops just a few people from using a service successfully, their needs take priority over the many people who might prefer but don’t need the feature.
Effectiveness for all users takes priority over efficiency or satisfaction for some users.
Find what works, not what’s popular
And you can get a printable version of the Find What Works, Not What’s Popular poster.
We’d love to hear your thoughts, either in the comments here, or through the feedback links on the guides.