Kuznekoff said that one of the biggest challenges teachers have in the classroom is the non-stop battle of keeping students working. He said many students felt they needed to be online and checking messages even when they had important work to do in class. The researchers said it is very common for students to be physically present in class, but mentally absent because they are using their mobiles. Kuznekoff said teachers were fighting a "losing battle" because students were more interested in social media than learning. The London School of Economics did a study in England and found that test scores increased by six per cent after mobile phones were banned in class.