  Films produced by assembling bare gold clusters well beyond the electrical
percolation threshold show a resistive switching behavior whose investigation
has started only recently. Here we address the challenge to charaterize the
resistance of a nanogranular film starting from limited information on the
structure at the microscopic scale by the means of Bruggeman's approach to
multicomponent media, within the framework of Effective Medium Approximations.
The approach is used to build a model that proves that the observed resistive
switching can be explained by thermally regulated local structural
rearrangements.
