New research from NPD In-Stat suggests that different tablet sizes have an impact on how people use the devices. Those in the 3.5-inch to 7-inch range, for instance, including personal media players, are best suited to everyday activities like commuting, exercising and other on-the-go uses. Tablets in the 9.7-inch-to less than-11-inch category are more likely to be used at home and for second-screen viewing. “As the tablet market continues to heat up, manufacturers are striving to differentiate next-generation products to compete with the iPad,” according to Stephanie Ethier, senior analyst, at NPD In-Stat. “Screen size has emerged not only as a key differentiator, but also the leading indicator of different tablet usages The research firm predicts worldwide shipments for devices with screen sizes between 3.5-inch and less than 7-inch will decline to 15.6 million by 2016. Despite continued price erosion, revenue for tablets in the 7-ince to 8.5-inch range represents one of the brightest spots in the tablet market because of strong anticipated demand for Amazon’s Kindle Fire. But led by the iPad, larger tablets will represent 65% of worldwide tablet shipments, according to NPD In-Stat. -- Mark Walsh