A tea bag is an extraordinary thing. Each small sachet contains a mix of leaves from different producers and different places. Hundreds of factors can affect the flavour of each leaf, from the amount of sunlight and rainfall to the type of soil it was grown in, how it was plucked and how it was dried. Yet when you drink a cup of your favourite brew, you expect it to taste exactly like the last one. Tetley, a British teamaker, boasts that its basic blend has had the same distinctive taste since the company was set up in 1822.

Researchers at the University of Wisconsin-Madison have built a robot, named Minnie, to serve as a reading buddy to middle school kids, and Minnie's new friends grew more excited about books and more attached to the robot over two weeks of reading together. "After one interaction, the kids were generally telling us that, sure, it was nice to have someone to read with," says Joseph Michaelis, a UW-Madison graduate student studying educational psychology. "But by the end of two weeks, they're talking about how the robot was funny and silly and afraid, and how they'd come home looking forward to seeing it again." Michaelis and computer sciences professor Bilge Mutlu published their work with Minnie on Wednesday (Aug. Research shows that social learning -- pairing up with a peer to complete math problems or read a chapter in a textbook -- is a powerful way to help students develop skills and interests, according to Michaelis.