One variation of a method for testing contact quality of electrical-biosignal electrodes includes: outputting a drive signal through a driven electrode, the drive signal comprising an alternating-current component oscillating at a reference frequency and a direct-current component； reading a set of sense signals from a set of sense electrodes at a first time； calculating a first combination of the set of sense signals； calculating a first direct-current value comprising a combination of the first combination and the direct-current component of the drive signal at approximately the first time； and at a second time succeeding the first time, shifting the direct-current component of the drive signal output by the driven electrode to the first direct-current value.
