This dissertation addresses the extent to which linguistic behavior can be described in terms of the projection of patterns from existing lexical items, through an investigation of Korean reduplication. Korean has a productive pattern of reduplication in which a consonant is inserted in a vowel-initial base, illustrated by forms such as alok-talok `mottled,' oto -poto; `chubby.' A wide range of consonants may be inserted, with variation both within and across speakers. Based on study of a Korean corpus as well as experiments in which native speakers formed reduplicated versions of nonce words, I argue that the choice of inserted consonants is affected by a complex set of factors, including syllable contact constraints, preference for particular consonant-vowel sequences, and tendency for inserted consonants to be distinct in place of articulation from neighboring consonants. The analysis in this dissertation shows that there is neither a single preferred consonant nor a random choice among all possible consonants. This phenomenon appears to contradict claims in previous literature concerning the identity of consonants inserted in reduplication. Contrary to the claim of Alderete et al. (1999) that segments in the reduplicant that are not present in the base represent an emergence of the unmarked, the inserted consonant (CI) in Korean reduplication cannot be an unmarked/default consonant because distinct consonants can be inserted in the identical environments, e.g. alok-talok `mottled,' ulak-pulak `wild' where /t/ and /p/ are epenthesized although the bases contain the same set of consonants, /l/ and /k/. Moreover, a particular vowel does not force the occurrence of a particular consonant, e.g. ulak-pulak `wild,' umuk- umuk `unevenly hollowed,' upul-k'upul `windingly' in which different CIs are followed by the same vowel /u/. Examination of the lexical patterns suggests that lexical frequency plays a role in the choice of inserted consonant. First, the frequency of CIs in a word creation experiment correlated significantly with the frequency of word-initial Cs in the Korean corpus. Second, the frequency of consonant combinations CI. C1 in forms of the shape CIV.C1VC2 correlated significantly with the frequency of combinations of consonants in CVCV forms in the corpus. Similarly, the frequency of combinations of CI. C2 in forms of the shape CIV.C1VC2 correlated with the frequency of combinations of onset C. coda C in the corpus. Third, the frequency of C. V combinations in the experiment correlated significantly with the frequency of lexical C. V combinations in the corpus. Another factor investigated was the effect of a restriction on syllable contact banning heterosyllabic sequences in which a coda C of a preceding syllable is of lower sonority than a directly following onset C. This restriction has been shown to play a role in Korean phonology, and is potentially relevant to choice of inserted consonant in reduplicants of the form VCVC-CIVCVC. This constraint was found to work more strongly for nonce reduplicated words than for the general vocabulary.The role of the following V on the choice of inserted C was also investigated. Korean speakers' behavior in many psycholinguistic experiments suggested that a CV (body) constituent is prominent for Korean speakers, as opposed to the speakers of English-like languages which evidently have a closer tie between V and C (rhyme). An additional factor that appeared to affect the choice of CI was identity avoidance. The general vocabulary of Korean was argued to respect an OCP-Place constraint (identity avoidance in place), which does not allow consonants with the same place to co-occur. The dictionary data and the experimental responses also showed significant effects of identity avoidance in place, based on the ratio of observed to expected occurrences of inserted consonants in different contexts. Data from the general lexicon and the reduplication data also revealed a distance effect: co-occurrence restrictions appeared to be stricter for adjacent consonant pairs than for non-adjacent consonant pairs.Lexical frequency was shown to play a role in the choice of inserted consonants, to some extent; however, individual speakers did not necessarily reflect the lexical patterns. There were two distinct patterns among the speakers with regard to the choice of CI: those who preferred /t/ predominantly over other Cs and those who preferred /_/ predominantly over other Cs. Moreover, within a group of the speakers who chose /t/ most frequently there were some speakers who chose less preferred CIs when the context contained their preferred CI, whereas other speakers stayed with the preferred CI regardless of context.