In the interactive reading model, comprehension is not just understanding words, sentences, or even texts, but involves building a model within the mind of the reader. This model leads L2 teachers to put an emphasis on teaching both linguistic features of the language and inference techniques to the learners. Sufficient attention, however, has not been paid to the latter in L2 reading classes. The aim of this study is to investigate the relationship between inferences in the L2 and three most important learner variables, L1 knowledge, prior knowledge and L2 proficiency. In order to accomplish this, the author first examines the concept, kinds, functions and main reading types of inference. Next, the review of relevant literature reveals that the learners' L1 transfer to the L2 reading is minimal unless their L2 proficiency reaches the threshold level. It is also found that the learners' background knowledge plays an important role in the comprehension of the L2 text by providing them with interpretive framework for the text comprehension and by compensating for their lack of vocabulary. Finally, the learners' L2 proficiency is another significant factor in reading. In particular, vocabulary ability in L2 contributes to the inference of the text by helping learners with processing meanings of the text automatically.
In conclusion, it is suggested that efforts be made to improve the learners' L1 reading skill, to activate their content schema and to enhance their vocabulary knowledge in L2 in order to help them maximize their L2 reading skill.