This chapter deals with the measurement of innovation activities, complementing the measurement of innovations as outcomes. It identifies eight major types of activities that firms may undertake in pursuit of innovation, namely research and experimental development; engineering, design and other creative work; marketing and brand equity activities; intellectual property; employee training; software development and databases; acquisition or lease of tangible assets; and innovation management activities. Acknowledging that these activities may be carried out for purposes other than innovation, this chapter provides guidelines for identifying the innovation-related content of resources dedicated to these activities. It also makes proposals for identifying follow-on activities to innovations as well as planned innovation activities and expenditures shortly after the reference year.