At low magnetic field, the magnetoresistance of LaAlO 3 /SrTiO 3 is parabolic versus field, as expected for an ordinary metal. However, at higher fields, the magnetoresistance appears to become linear versus field. Linear magnetoresistance can have many causes, but so far there is no scientific consensus on the cause of linear magnetoresistance in LaAlO 3 /SrTiO 3 interfaces. Linear magnetoresistance has also been measured in pure SrTiO 3 crystals, so it may be unrelated to the emergent properties of the interface.