One variation of a method for testing contact quality of electrical-biosignal electrodes includes: outputting a drive signal—including an alternating-current component oscillating at a reference frequency and a direct-current component—through a driven electrode； determining that a reference electrode is in improper contact with a user's skin if a reference signal read from the reference electrode excludes a first signal component oscillating at the reference frequency and a second signal component oscillating at an ambient frequency； determining that a sense electrode is in improper contact with the user's skin if the reference signal includes the first signal component and if a sense signal read from the sense electrode excludes a third signal component oscillating at the reference frequency； and generating an electrode adjustment prompt if one of the reference and sense electrodes is determined to be in improper contact with the user's skin.
