Effects Of Different Information Processing Methods Of Encoding And Retrieval On L2 Phrasal Verb Acquisition

Encoding of the memory process is widely regarded as the key to the memorizing quality, while retrieval merely as the test of the previous encoding effect. However, many studies at the field of cognitive psychology have recently found the retrieval practice effect: compared with the simply repeated study or even the elaborative study in the equivalent amount of time, taking one or more tests would significantly facilitate the long-term retention of target materials, and it would also promote the future retrieval and transfer in different knowledge domains. However, the previous studies mainly focus on the comparison of encoding and retrieval. Few of them explore the effect of the combination of encoding and retrieval. In addition, there are limited studies investigating the retrieval practice effect in SLA, and the researches on L2 phrasal verbs center all the more on the encoding period. Thus, it is worth further exploring whether the retrieval of L2 phrasal verbs will facilitate their acquisition. The present study is conducted with the theoretical underpinnings of Levels of processing theory and the relevant mechanisms of retrieval practice effect, and employs the quantitative research method combined with the qualitative one, to investigate the following questions:1. How do different information processing methods of encoding and retrieval(repeated encoding; encoding before retrieval; retrieval before encoding) affect L2 phrasal verb acquisition?2. How does the effect vary with language proficiency under the different information processing methods?172 subjects were randomly divided into three groups: repeated encoding group(EE group), encoding before retrieval group(ER group) and the retrieval before encoding group(RE group), in which 79 English majors from one of China’s national key “211 Project” universities as the high proficiency(HP) subjects, and 93 non-English majors from one vocational college as the low proficiency(LP) ones, all of them being freshmen. There existed significant within-group difference but no between-group difference among the subjects with two different L2 proficiency levels. All the learners accepted explicit instruction and the criterial test after instruction(TAI), and there was no significant difference in the initial study period among these three groups. Two weeks later, the subjects were required respectively to complete the following tasks: 1) EE group restudied the target material twice; 2) ER group first restudied the target material and then finished the retrieval practice task; 3) RE group first completed the retrieval practice task and then restudied the target material. Then the immediate posttest was conducted and two of the subjects in each group were interviewed(these 12 interviewees’ quantitative data would not be counted in final results). Last, the delayed posttest was conducted two weeks later.Research results and analysis are summarized as follows:First, different information processing methods of encoding and retrieval affected the storage quality and memory strength of L2 phrasal verbs.Whereas EE group significantly outperformed the RE group in the productive test of the immediate posttest, ER group performed remarkably better than RE group in that of the delayed posttest. This result demonstrated that the timely and sufficient encoding after the initial study would significantly facilitate the short-term memory of the orthographic forms of target terms. Compared with the method of encoding before retrieval, however, the method of repeated encoding created less enhanced memory trace or less retrieval routes, thus produced less long-term retention than the former. On the contrary, retrieval based on insufficient encoding would induce learners to allocate the main attentional resources to the corresponding L1 meanings of the target phrasal verbs, which resulted in superficial and imprecise processing of the target terms’ orthographic forms. Thus the method of retrieval before encoding produced less positive effect on L2 phrasal verb acquisition than the other two methods.Second, the positive effect of retrieval practice on L2 phrasal verb acquisition and retention increased with the improvement of L2 proficiency.1) As for the LP learners, both the EE and ER groups significantly outperformed the RE group in the immediate posttest. Due to the learners’ low prior knowledge, the initial encoding of target terms was not sufficient. Thus the retrieval task based on the insufficient encoding impeded the further processing of target items. Besides, LP learners suffered more pressure and anxiety from the retrieval task, which induced negative effect on their performance. The repeated encoding showed less advantage on the long-term retention of target terms’ meanings, while the retrieval after encoding facilitated the digestion and internalization of linguistic knowledge and promoted the long-term retention. 2) As for the HP learners, different information processing methods did not affect their immediate performance due to their solid knowledge of target phrasal verbs, flexible avoidance of distractors and high capability of self-correction. However, retrieval task stimulated the relevant semantic network of target terms and multiplied or elaborated the routes for future retrieval. In addition, the mediators generated during the encoding period also helped learners to search for target items. Therefore, retrieval practice produced better effect on the long-term retention, which demonstrated the ideal effect of the combination of encoding and retrieval.The present study provides some pedagogical suggestions: 1) With sufficient encoding as prerequisite, the combination of encoding and retrieval positively affects the L2 phrasal verb acquisition. Therefore, the retrieval practice should be conducted based on the full comprehension of target materials especially for LP learners. 2) L2 proficiency differently affects the effects of different information processing methods. The educators’ instruction should be conducted according to learners’ language proficiency for better teaching results.