Apple will face its fiercest struggle yet in the tablet space this holiday season, as rivals put forward their strongest tablets to compete with the market-leading iPad. As the firm prepares to release widely expected updates to its tablet line Tuesday, it may have to work harder to convince consumers to spend money on an Apple tablet.

When Apple introduced the iPad in 2010, it set off a sea change in personal computing — very similar to how it upset the mobile phone market with the iPhone. And just as Apple faced growing competition from Samsung and other tech firms who followed the iPhone with cheaper or more specialized smartphones of their own, the iPad is also watching rivals gain ground.

“At a time when the smartphone and tablet markets are showing early signs of saturation, the emergence of lower-priced devices will be a game-changer,”said Megha Saini, an IDC research analyst in a report last month. These lower-priced tablets could see particular success, the research firm said, among institutional consumers, such as schools and businesses.

As more people pick up tablets and look for ways to slot them into their lives, it’s become clear that one size may no longer fit all. Apple itself acknowledged this last year with the launch of the 7 iPad mini — one of the products expected to get an upgrade on Tuesday — which Apple launched to get a piece of the interest generated by similarly sized tablets from Amazon and Google.

Samsung and Microsoft, particularly, have been aggressive in commercials about highlighting how their products differ from Apple’s on the productivity front. Both have introduced tablets with styluses and keyboards that are aimed at tablet buyers who want to use their devices for work. While these firms have seen far less success than Apple in the tablet market thus far, they are picking up followers — and have the money and patience to grow larger audiences.

Meanwhile, the tablet market overall is continuing to grow. Analysts from the International Development Corporation expect tablet shipments to outstrip personal computer shipments in the last quarter of 2013.

Apple is still the leading tablet manufacturer in the world with 32 percent of the tablet market in the second quarter of 2013, according to IDC — down from 60 percent in the same period last year. Part of the slump could be attributed to Apple not having released a tablet in about a year. In that period, rivals such as Amazon, Google, Samsung, Nokia and Microsoft worked hard to improve the quality of their tablets to erode Apple’s share of the market.

But while new models should help boost Apple’s share of the market, the Gartner analysis firm now reports that tablets running Google’s Android operating system and those running Apple’s iOS each make up about half of the world’s tablets. The two firms are expected to stay in a neck-and-neck position throughout 2014.

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