syllables into groups that are phonetically most distinct from each other. Phonologically complex distinctions are those which exceed an upper threshold in the number of phonological predicates to which they refer. It is claimed that languages adopt weight distinctions that are phonetically most effective without being overly complex phonologically. Syllable weight thus reflects a compromise between phonetic and phonological factors. The proposed model of weight further suggests that phonological weight distinctions are ultimately predictable from other basic phonological properties, such as syllable structure.* 1. SYLLABLE WEIGHT. Linguists have long observed that certain phonological processes in many languages distinguish between 'heavy' and 'light' syllables (see, for example, Jakobson 1931, Trubetzkoy 1939, Allen 1973, Hyman 1977, 1985, 1992, McCarthy 1979, Zec 1988, Hayes 1989). Syllable weight has played an increasingly larger role in more recent phonological theory, as the number of prosodic phenomena argued to instantiate syllable weight has grown to encompass diverse phenomena such as weight-sensitive stress, compensatory lengthening, reduplication, minimal word requirements, and tone, among others. Drawing on data from these weight-sensitive phenomena, linguists have developed simple yet compelling theories of weight grounded in fundamental concepts such as phonemic length, segment count, and sonority. As our data base on weight-sensitive phenomena has expanded to include ever more explicit information on a larger cross-section of languages, theories of weight have been presented with new and interesting opportunities for empirical validation. While the expanded empirical base has corroborated many standard notions about syllable weight, it has also brought new challenges to the theory of weight: an increasingly diverse set of weight distinctions crosslinguistically, individual languages sensitive to multiple weight distinctions, weight distinctions based neither on the number of segments nor on phonemic length contrasts, and cases of conflicted weight criteria for different weight-sensitive processes in the same language. These new data continue to necessitate expansions of the formal apparatus in the theory of weight, suggesting the need for reexamination of the phenomenon of syllable weight. This article explores the extent to which syllable weight is linked to both phonetic and phonological properties. As such, it may be viewed as part of two research programs: one relating the phonology and phonetics of weight (see, for example, Maddie