The paper compares the effectiveness of three types of input enhancement treatments for EFL students' learning of collocations. A total of fifty-seven non-English-major freshmen participated in the study. They were required to undergo three experiments conducted at separate times, each containing a treatment followed by a collocation test. The results of the study indicated that the use of perceptual salience alone, though maybe helpful for the noticing of the target collocations temporarily, is insufficient for the development of awareness of the target collocations. The combination of perceptual salience and relevant metalinguistic knowledge was more effective. With the help of the latter, the learners had an understanding of the concept of collocation and the features of the target collocations, which, in turn, helped the learners not only to notice the target collocations in input but also to develop conscious awareness of them. Nevertheless, the mixture of perceptual salience, coupled with relevant metalinguistic knowledge and a consciousness-raising activity worked most effectively for the learning of collocations. The learners' engagement in the consciousness-raising activity enabled them to interact with the target collocations and to internalize the target collocations for production. Accordingly, the findings of the study rejected the weak version of the Noticing Hypothesis on the one hand and supported the strong version of the Noticing Hypothesis on the other hand.
