Tablets will become most users' main computing devices within the next four years, Forrester Research analyst Frank Gillett has predicted.

Gillett recently forecast that some 375 million tablets will be sold globally in 2016 -- compared to around 56 million in 2011. That prediction is nearly double the amount projected by IDC, which said worldwide tablet sales will hit 200 million in 2016.

There is one major reason for the different predictions: In Gillett's report, tablets figure prominently in many settings, including the workplace, where the devices are useful for sharing and working in groups. "There's no barrier of a vertical screen, no distracting keyboard clatter, and it just feels natural" to share a tablet among co-workers compared to "spinning around a laptop," Gillett wrote in his blog.

For these reasons, " tablets will become the preferred, primary device for millions of people around the world," he said.

In 2016, one-third of the tablets sold will go to business users, Gillett said. The total installed base of tablets by that year is expected to reach 760 million.

Gillett defines a tablet as a device that sports a touchscreen between 7 in. and 14 in. in size, weighs less than 1.75 lbs., has an eight-hour battery life and allows always-on operation.

Even with all the tablet growth, Gillett doesn't see PC sales stopping. "Eventually," he explained, "tablets will slow laptop sales but increase sales of desktop PCs" for creative work that requires major processing power or a large display.

This version of this story was originally published in Computerworld's print edition. It was adapted from an article that appeared earlier on Computerworld.com.

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