The purpose of this study is to examine the effects of definition placement and meaning inference on EFL learners' contextual vocabulary learning by viewing video and on the learners' perception of their learning. The participants were 33 Korean elementary school students and 11 Korean middle school students. Both quantitative and qualitative data were collected by administering pre, post, and delayed post-tests and conducting surveys over a three-week period. The participants were divided into three groups, and they encountered four target vocabulary items twice by viewing two videos in English with English subtitles under three different conditions. The first group (n=14), under errorless conditions, learned the definition of the target vocabulary before viewing the videos and the meaning inference after viewing. The second group (n=15), under trial-and-error conditions, watched the videos first, then inferred their meanings and the definition of the target vocabulary. The last group (n=15) made meaning inferences only after viewing the videos without first learning the definition. Prior to the treatment, students from all groups completed a pre-vocabulary test and a pre-survey. During the treatment, they completed a post-vocabulary test and the inference worksheet. A week after the treatment, they completed a delayed post-test and a post-survey to see the difference in the participants' perception of their vocabulary learning.
The results of the vocabulary tests revealed that the group under trial-and-error conditions benefited more in terms of short-term vocabulary meaning recall and long-term vocabulary meaning retention than the group under errorless condition. The inference worksheet responses by the group under trial-and-error condition were more accurate than other groups. The last group under the erroneous inferencing condition was the least effective with short-term vocabulary meaning recall and long-term vocabulary meaning retention when the exercise was not followed by definition and the students remained uncorrected. Inference accuracy was not reliable in the group. The survey results showed no difference in the participants' perceptions of their vocabulary learning.
Thus, the results of the present study suggest that poviding the definitions of target vocabulary after a contextual encounter such as watching videos with subtitles may have benefits for vocabulary meaning recall. These findings encourage EFL students to infer meanings of unfamiliar words based on contexts before looking up their meanings in dictionaries. Even EFL teachers and course material developers should note that providing definitions after a contextual encounter is more beneficial for enhancing students' vocabulary knowledge rather than presenting definitions before they see them in writing.