Herein is disclosed a method and apparatus for controlling a lapping process, so as to create a read/write head that contains a primary magnetoresistive read element with a desired stripe height. An improved lapping guide is achieved by incorporating a secondary magnetoresistive element into a read/write head. By virtue of its location on the same read/write head as a primary magnetoresistive element (used for reading data during operation of the disc drive), the secondary element is located in close proximity to the primary element, resulting in smaller tolerances in aligning or relating the top edges of the primary and secondary elements. Accordingly, the secondary magnetoresistive element more reliably serves as a proxy for the primary element. Optionally, the secondary magnetoresistive element may be fashioned with identical dimensions as the primary element, so as to render the secondary element equivalent to the primary element with regard to magnetic sensitivity. During lapping, the magnetic sensitivity of the secondary magnetoresistive element is monitored and used as a proxy measurement of the magnetic sensitivity of the primary magnetoresistive read element.