The Meyer-Neldel rule or the Compensation Law linking a larger activation energy to a larger preexponential factor of the d.c. conductivity and found to hold in some families of ionic conductors is discussed in the framework of the Coupling Model. When certain conditions are satisfied, it is shown how the Meyer-Neldel rule can originate from the cooperative dynamics of ionic motions. Not so well known is the anti Meyer-Neldel rule, which has the opposite behavior. Using the system (AgI)(x)(AgPO3)(x-1) for 0 less than or equal to x less than or equal to 0.6 as an example, we propose a possible physical origin of the anti Meyer-Neldel rule.