Jakob Nielsen's latest Alertbox summarises the results of the Nielsen Norman Group's second study into the usability of iPad apps and websites accessed on an iPad.
For me the most interesting insight was that unless the primary user lives alone, their tablet is likely to be shared with their partner, children and visiting friends. NN/g concludes that "Tablets are shared devices" and that when designing apps for a tablet "you should assume that you're designing for a multi-user device."
Yet few tablet operating systems provide good support for shared use (driven by its need to control access to sensitive business data, the Blackberry Playbook is a rare exception). And this can lead to significant problems for users. Young children accidentally change settings, delete work emails and reset the game scores of older siblings. Teens move apps between folders, access age-inappropriate games and media, and use stored account and payment information to make unauthorised purchases. Partners must frequently log in and out of each other's Facebook, Twitter, Google and other accounts.
Working your way through these sharing problems is hard work for even the geekiest of us. And while some apps do provide simple ways to control access to multiple Facebook, Twitter and eMail accounts, users must learn the sharing features of each app and create a separate profile in each one.
This again demonstrates how important it is to investigate and understand people’s real behaviour and contexts of use when designing for new platforms.
So when we design tablet apps, we must consider carefully, whether and how to support shared use. Will users each want their own settings and data? Will adults need to protect some sensitive data from their children? If your app connects to a website or web service, will different users need to connect to different accounts? If you do need separate user profiles, how will you store and how will your users manage them?
NN/g's research and the multi-user support within many apps, suggest that better support for shared use should be a priority for tablet operating systems. The access experience could be very simple: tap your name and enter a password/code, or even just show your face to the camera. And while each app would still need to decide how it handles multiple users, standard APIs and common interface guidelines would make life easier for designers and developers. And most importantly, make the experience of sharing more simple and more consistent for users.