Abstract: A multiple site probe for simultaneous probing of multiple chip site clusters of pads. The multiple site probe assembly includes a mounting plate having a plurality of groups of adjustably mounted probes thereon. A plurality of cams cooperate with cam followers associated with individual groups of probes, each of the cam and cam followers having a displacement which is dependent upon its distance from a predetermined and fixed reference relative to the mounting plate. An actuator is connected to the cams so as to effect simultaneous actuation of the cams and to allow for differential displacement of each group of the groups of probes so as to compensate for accumulated tolerances and/or shrinkage of the substrate.