Media richness has been defined in the literature in terms of four objective characteristics. A rich medium is one that allows for communication of multiple cues through multiple channels, language variety, immediate feedback and a high degree of personalness (Lengel, 1983; Daft and Lengel, 1986). When this concept is applied to traditional forms of communication, face-to-face interaction is considered to be the richest, followed by the telephone, a letter, a memo and a flyer/bulletin (Lengel, 1983;Trevino, Lengel,Bodensteiner, Gerloff and Muir, 1990). With the acceptance and general use in recent years of electronic forms of communication, such as electronic mail, it is of interest to examine where along this continuum of media richness the new electronic forms lie. This is important to ascertain because the so-called "richness imperative" suggests that high-rich media are necessary for the effective handling of equivocal situations, while low-rich media are sufficient for situations that are low inequivocality (Trevino et al., 1990). Thus, it is useful to know which media are rich and which are not in determining how to apply the above rule. Electronic mail (E-mail) is a commonly used electronic communication medium. It can be classified as a relatively low-rich, or lean, medium according to the four characteristics of richness. In using E-mail, one is not able to communicate through multiple cues or multiple channels, use of much language variety is limited, immediate feedback may or may not be possible depending on the availability and inclination of the communication partner, and based on the required use of a computer and the written word, it is not generally viewed as a personal mode of communication. However, according to some recent studies in the literature, there is some evidence that E-mail is perceived by its users to be a richer communication medium than its objective characteristics would indicate (Fulk, Schmitz and Ryu, 1995; Kydd and Ferry, 1992; Markus, 1994; Lee, 1994). This suggeststhat there may be subjective factors involved in determining the richness of a medium in addition to the objective characteristics. Thus, we need a way of capturing these subjective factors that will allow us to understand why E-mail (and perhaps other communication media) is perceived to be richer than that dictated by the definition of richness. The purpose of this research is two-fold. First, we suggest that the way in which richness has been measured in the past is not sufficient to allow us to truly understand why E-mail and other electronic media are viewed as either rich or lean. Second, we develop and test an instrument for measuring media richness based on the original definition and description. Lengel (1983) originally used a 100-point scale to measure the richness of traditional communication media such as the telephone, a formal memo and a letter. Trevino et al. (1990) used the same scale to measure the richness of electronic mail and found that it was rated at approximately 75. Unfortunately, this tells us nothing about why respondents evaluated E-mail richness as they did. Is it personalness, feedback, or some other dimension? This research attempts to develop a more robust instrument for measuring richness directly by measuring the four characteristics specified in the definition. There is a precedent for this in Fulk et al. (1995), who took the first step in measuring richness in this way by asking one question per characteristic. We propose a fuller instrument that includes several items percharacteristic which can then be folded into a composite measure of media richness.