Is it Usable Enough?

A common question Clients, Stake holders, Product Managers and even my colleagues often ask me is – “Is it Usable enough?”. What they want to know is, if enough user testing has been done and if the product is ready to go live into production. So, how do you answer this question?

First, let us see the two different ways to measure the overall usability:

1. Quantitative: So 4 out of your 5 users have successfully completed the user test. 80% seems like a really good pass percentage. But, is testing 5 users enough? And with tight releases, you don’t normally have the time to recruit and keep testing users. This is where companies like Google and YouTube have a big advantage. They live test their designs with millions of their users, and in no time they have enough test data to determine if the design is usable or not.
Analytics is another quantitative way to measure usability. Again, if you have a small user base or if you are launching a new product, it takes time to collect enough data.

2. Qualitative: So 4 out of your 5 users have successfully completed the user test. But the 5th user failed miserably in his task. This is where the design team has to make a decision. If they feel that the user who failed to complete the test was just an one-off case, and similar situation will almost never replicate, then they go ahead with the release. If not, they need to test more users. And if there is a time constraint, they need to trust their skills and make changes to the design.

So how do you decide ‘if it is usable enough?’. It is not just about reaching a predefined number of users who successfully complete the test. Neither is it just about keeping on testing users until you reach a stage where no user is flabbergasted. It is actually the combination of both. The right balance depends on your product, users, design team, development/release cycle and the organization as a whole.