A shaker apparatus (10) and method for carrying and vibrating a device to be screened, comprising exciter means (50) secured to a mounting table (20) having a plate (100) for imparting excitations thereto, mounting means (4) coupled to the mounting table (20) for mounting the shaker table to a foundation (2) and for substantially isolating vibration of the mounting table (20) from the foundation (2),dispersive means defining a plurality of cavities (106, 108) in the plate (100) in a predetermined array, and means defining holes (102, 104) in the plate (100) and a mounting sheet (122) of the table for mounting thereon the device to be screened, the dispersive means dispersing unidirectional excitations imparted to the table into substantially incoherent multiaxial and multirotational directions.