This research posits a new measurement instrument of the Interactivity construct. This operationalization is based on Steuer’s (1992) conceptualization. Steuer (1992) proposed a definition of Interactivity based on the three sub-factors of speed, range, and mapping. However, no articles found in a citation track of Steuer (1992) used these sub-factors in measuring the construct. In order to provide a foundation for further work in this area, measurement items were developed to model interactivity as a formative second-order factor as proposed by Steuer (1992). Two laboratory experiments are used for this purpose. Results from the first exploratory study are presented and identify measurement items for the three sub-factors identified by Steuer (1992). The second study is proposed to confirm the results of study one by statistically comparing the developed instrument to existing instruments, and testing relationships between interactivity and other constructs that have been previously proposed in IS research literature.