Calculation of the dielectrophoretic (DEP) force on a neutral dielectric partide in a nonuniform electric field is simplified by using the effective dipole method. Once the instantaneous effective dipole moment peff(t) has been correctly identified using Gauss's law, then the expression (peff(t)Â¿)E0(t) is used to determine the force on the particle. Recent work has demonstrated that the effective dipole method produces a result consistent with integration of the Maxwell stress tensor. In the present paper, the issues concerning identification of peff(t) are aired, and an alternate derivation of the DEP force on a conducting dielectric sphere immersed in a conducting dielectric fluid is offered. Then the effective dipole theory is generalized to account for higher order (multipole) contributions. This new effective multipole theory is restricted to spherical particles in a cylindrically symmetric cusped electric field, but the analysis leads to straightforward computation of the quadrupolar correction factor for the DEP force. A quantitative example is provided.