Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining the identity of an object in an image where the object in the image is in a disassembled state. In one aspect, a method includes accessing previous interactive sessions, each of the interactive sessions including images of a reference object in one or more disassembled states and each of the interactive sessions specifying an identity of the reference object in an assembled state; processing an image of a first object to identify characteristics of the first object, the first object being in a disassembled state in the image; comparing the image of the first object in the disassembled state to images of reference objects in disassembled states; and determining an identity of the first object based on the comparison and the identities of the reference objects in assembled states specified in the interactive sessions.