It is well known that the use of mobile devices for accessing the web and online services is increasing. In addition, the use of social applications from mobile devices such as smartphones is also increasing, with Apple and Google platforms being the leaders.

With the increasing use of mobile devices as the ‘device of choice’ to assess the web, it was interesting to read a recent blog by Jakob Nielsen on a preliminary usability assessment of the iPad including some comparisons between the iPad and iPhone. Here are some of the main points that I gleaned from the assessment and what it means for usability with mobile devices.

Usability challenges – fat finger problem

With the iPad, regular websites worked “reasonably well” while iPhone users preferred the use of mobile applications, finding regular websites difficult to navigate on the relatively small display. Mobile friendly websites are increasing, but some mobile sites may still provide some usability challenges.

To facilitate touch-screen devices such as the iPad, iPhone and Android based phones, websites / applications should have large touch zones to avoid the “fat finger” problem. The risk of accidental activation is a challenge for most mobile interfaces.

UI consistency between apps

With many of the iPad applications, any image on the screen can be a possible user interface, yet most of these images were flat, whereas user interface design guidelines recommends scroll-bars and buttons to be raised or etched in order to distinguish them. There is little consistency between applications in relation to user interaction – touching an image in one application may trigger one type of action, while touching an image in another application may trigger no action. So the use of generic commands across all mobile applications would help greatly with usability.

User empowerment vs. Author authority

Nielsen refers to the challenge for the iPad’s (and I presume other mobile devices) user experience between user empowerment or author authority. Generally with the web, the user is ‘empowered’ to browse where they like, moving from link to link. With the iPad, Nielsen sayes that “current design strategy of iPad apps definitely aims to create more immersive experiences, in the hope of inspiring deeper attachments to individual information sources”.

Deeper attachment means less movement between websites. This differs from previous experiences of the web, where the user’s ease of movement drove websites to conform to a common set of conventions for using the web.

Are you a card shark or holly scroller ?

Jef Raskin – a user interface design pioneer – coined the phrase card shark or holly scroller . Traditionally, the web and most mobile phone applictations are places for scrollers with the ability to scroll through data. In the initial designs of the iPad, the card sharks may be holding the upper hand, where the focus is on providing a fixed space for providing information with minimal scrolling. The relative merits of either model are not discussed, so this is simply an observation and there is no reason that both models cannot co-exist, depending on user preferences.

To sum up

The iPad is still evolving, so as future versions are released, it will be interesting to see how usability evolves and whether the iPad is used as a ‘leisure’ device with the work related activities being done on the desktop and the mobile phone.

The iPad usability blog also contains a link to the full report for download and a short video demoing some of the usability issues. In addition here is a link to an interview with Jakob Nielsen on Guardian Tech Weekly podcast about the iPad usability assessment.