A couple of months ago, I wrote a blog post about the myriad of mobile, tablet and desktop devices that a website can potentially find itself having to address. My conclusion on the way to approach this was:

"For complicated and immersive tasks, look to the desktop first and then consider offering a simplified version for the mobile web – or even a set of mobile websites for individual tasks. Conversely, for simple and infrequent tasks, look to mobile first. Where mobile is likely to be part of the mix from the outset, look to the mobile web before looking at apps, so as to start with a consistent user experience across all device types, before introducing variations for apps to cater for platform requirements."

Part of the reason for my being cautious about the idea of designing sites for mobile first in all cases is that the history of computing to date is that users are continually demanding larger screen resolutions, which suggests to me an inherent limitation on the types of task that mobile is well suited for. So, I was rather pleased to find Jakob Nielsen takes exactly the same view:

"Desktop PCs have 2 inherent advantages over mobile:

  • Much larger screens, letting users see more information at a glance. This enhances content comprehension, facilitates navigation and interleaved browsing, and supports compare-and-contrast tasks, which are often the most critical high-value tasks.

  • Better input devices, with a big keyboard and a real mouse.

Big screens and big input devices are both inherent advantages of the desktop PCs; mobile devices must be small so users can carry them around... I am a screen-size bigot: bigger screens deliver hugely higher user productivity. Anyone who's experienced a 30-inch monitor cringes at the idea of doing a major project on anything smaller.

Much use will... shift from desktops to phones and tablets, but a big percentage of use will remain on the desktop. It's hard to estimate the exact percentage for each device class, but it's fairly certain that the highest-value use will stay predominantly on desktop. Thus, the percentage split of value between devices will be more favorable to the PC, even if the percentage split of time increasingly turns more toward tablets and phones.

We've known since our early mobile user research in 2000 that killing time is the killer app for mobile devices. This again means that much small-device use is fairly low value: playing casual games, checking social network updates, reading celebrity gossip and other generic news, and using intermittent-use apps."

Nielsen goes on to say that he envisages most high value tasks sticking with the desktop, including most enterprise, B2B, ecommerce (where only 2% of transactions are conducted on mobile) and any complex tasks; into which cateory, I think we can probably place much of academic research activity into this category.