As a replication study of Hanaoka and Izumi (2012), the present research investigated the process of learners’ noticing of problems in their interlanguage (IL) while they were producing the second language (L2) and their process of relevant input provided in the form of two types of feedback (i.e., reformulation and a model text) in L2 writing. The data were collected from twenty-five university students in Korea, and they engaged in a four-staged picture description task consisting of the writing stage (Stage 1), the comparison stage (Stage 2), the immediate revision stage (Stage 3), and the delayed revision stage (Stage 4). It was found that output triggered learners’ noticing of problems; however, the problems did not always show up overtly in their writing. Some problems were manifested in writing (i.e., overt problems), while some were hidden (i.e., covert problems). A model text and reformulation played somewhat different roles in offering the solutions to the problems: a model text provided more solutions to covert problems while reformulation provided more solutions to overt problems. And, the extent of learners’ noticing was associated with the types of problems (overt vs. covert problems) and feedback (i.e., models vs. reformulation). However, the types of problems and feedback were not related to the rate of incorporation of feedback into subsequent writing.