Effects Of Retrieval Difficulty And Feedback On L2 Vocabulary Learning

Testing effect refers to the phenomenon that retrieval of information from memory produces better retention than restudying the same information for an equivalent amount of time.In order to achieve efficient learning,nowadays more and more researchers have begun to focus on how to get the optimal testing effect.It has been found that testing effect is affected by retrieval difficulty,feedback and other factors.However,there are still some disputes.Besides,there are few attempts and little consistency with regard to the interaction between retrieval difficulty and feedback on memory retention.Furthermore,researchers have found that,in addition to promoting memory retention,tests also have a certain impact on metacognition.Accurate judgments of learning(JOLs)can help learners monitor following learning.But relevant research is little.Therefore,the present study aims to explore the impact of retrieval difficulty and feedback on L2 vocabulary learning in terms of memory and metacognition.The research questions addressed are as follows:(1)How does retrieval difficulty(recognition and recall)affect L2 vocabulary learning and JOLs?(2)How does feedback(with feedback and without feedback)affect L2 vocabulary learning and JOLs?(3)How do retrieval difficulty(recognition and recall)and feedback(with feedback and without feedback)interactively affect L2 vocabulary learning and JOLs?Two hundred and twenty eighth graders enrolled at a junior high school in Wuxi randomly made up 4 experimental groups: recognition(RC),recognition with feedback(RCF),recall(RE)and recall with feedback(REF),and 1 control group: restudy(RS).Participants in both control and experimental conditions were assigned with an initial encoding session.They were asked to study 15 English-Chinese pairs.Then they were instructed to receive different intervention operations.Participants in control condition were asked to restudy the same materials.Participants in RC and RE group were separately given a recognition or recall test.Participants in RCF and REF were asked to take a recognition or recall test,and then received and learned the feedback provided.After intervening tasks were completed,all participants did judgments of learning immediately.Then students were instructed to finish the final recall and recognition tests.At last,all participants received a questionnaire survey and 2 students in each group were chosen to do an interview.A week later,all participants took a delayed test consisting of both recall and recognition.The major findings are summarized as follows:(1)Retrieval difficulty does significantly affect learners’ L2 vocabulary learning and JOLs.In terms of L2 vocabulary learning,similar operations on initial and final tests lead to better performance in immediate test,which supports transfer-appropriateprocessing view.But in delayed test,taking an intervening recognition test boosts final test performance more than taking an intervening recall test,regardless of whether the final test is recognition or recall format.This is because too much retrieval difficulty of L2 vocabulary recall results in retrieval failure.In terms of JOLs,whether in immediate or delayed tests,JOL magnitude of recognition is higher than that of recall,but its absolute accuracy is lower than that of recall.The reason for this finding is that recognition retrieval is easier and more fluent,thus leading to higher JOLs,but these judgments are not in accordance with actual performance.(2)Providing feedback doesn’t significantly affect L2 vocabulary learning,but does have marginally significant effect on JOLs.In terms of L2 vocabulary learning,feedback doesn’t make any differences in both immediate and delayed tests.One possible reason may be that the feedback provided is immediate feedback;it is easier to produce cognitive interference to initial tests.Besides,target lexical form may also weaken the effect of feedback due to its comparatively low cognitive complexity and abstractness.Furthermore,the time providing feedback is relatively short,which will be another reason that leads to participants fail to benefit from feedback.In terms of JOLs,adding feedback increases JOL magnitude relative to conditions taking a test without receiving feedback,but decreases the absolute accuracy of these decisions.According to fluency hypothesis,providing feedback facilitates the ease of processing,so participants give higher JOLs.But feedback makes metacognitive judgments less accurate,because it fails to enhance learning.(3)Retrieval difficulty and feedback do interactively modulate L2 vocabulary learning in a complicated way,but no interaction effect is found in JOLs.In terms of L2 vocabulary learning,when final test is recall,adding feedback does affect the magnitude of testing effect caused by initial recognition and recall.More specifically,providing no feedback is found to boost final test performance more than providing feedback when taking an initial recognition test,but when taking an initial recall test,receiving feedback is much better.This is because desirable difficulty resulted by providing no feedback is beneficial to retention when initial test performance is good,but when initial test performance is poor,there are more opportunities for feedback to correct errors and ameliorate final performance,thus producing better effect.But when final test is recognition,there is no such interaction.The reason for this may be that recognition test is very easy,so feedback does not make a difference.In terms of JOLs,there is no interaction between them whether in immediate or delayed tests,which maybe is caused by the strong main effect for retrieval difficulty.The results obtained in the present study have significant pedagogical implications.Firstly,L2 teachers should be good at using tests in education and instruct students to develop self-testing habit.It helps students promote knowledge retention and make more accurate JOLs.Secondly,L2 teachers should provide students with appropriate test formats based on the different difficulty levels of knowledge.The tests with greater retrieval difficulty usually can lead to better retention effect and more accurate decisions,but too much retrieval difficulty can also result in retrieval failure.So L2 teachers should provide feedback if necessary.Desirable difficulty is conducive to memory retention and proper feedback can ensure correct rate.It makes students have a great willingness to take tests and make good use of tests.