This thesis summarizes and reviews the empirical literature on organizational ambidexterity and compares four distinct approaches to measuring exploration and exploitation: patent-based measures, survey-based measures, accounting-based measures, and press-based measures. I argue that press-based measures can be an effective way to measure exploration and exploitation longitudinally. However, such measures must be tailored to specific industries, and therefore I suggest strategies and procedures for constructing valid and reliable press-based measures in a single industry context. I illustrate my arguments through a study of the worldwide optical disk industry.