Spokes and matrix models. In order to represent the complexes identified by the AP-MS methods as binary pairs, the spokes model (a) or the matrix model (b) can be used. In the spokes model, it is assumed that only the tagged protein interacts with the other proteins in the complex. In the matrix model, it is assumed that all proteins in a complex interact with each other. While the spokes model probably leads to an underestimate of the real interactions, the matrix model leads to an overestimate.