A longitudinal investigation of the impact of code-switching versus target language only on Saudi EFL students’ written receptive vocabulary knowledge development in terms of breadth

This longitudinal research was conducted to investigate the effect of code-switching versus target language only on Saudi students’ written receptive vocabulary knowledge development in terms of breadth. A total of sixty male samples were randomly chosen from the population of Saudi EFL students at Jouf University in Saudi Arabia who enrolled in extensive English courses. This course is provided for those who scored less than the direct admission score of 2.5 out of 5 in the English replacement test. Samples were equally divided and allocated into two classrooms. In the first class (i.e., C1), thirty students were instructed by a non-native English speaker who employed code-switching as a pedagogical strategy. Students in the second class (i.e., C2) were instructed by non-native English speakers who employed the target language only as a pedagogical strategy due to the different language backgrounds between the instructor and participants. Data were collected from samples of both classes using the Vocabulary Size Test developed by Nation and Beglar (2007) at four different intervals and over four months (i.e., one academic semester). Results revealed that Saudi students’ vocabulary knowledge in terms of breadth had developed significantly at four different intervals in both classes. However, the development in C2 where the instructor employed the target language only, was significantly higher than in C1 where code-switching is employed. Moreover, results also indicated that samples in C1 where code-switching is employed experienced a newly coined linguistic status called Receptive Vocabulary Recission (RVR) which indicates the act of avoiding the acquisition of new English vocabulary since they were habituated to be given an additional explanation for new vocabulary using their first language knowledge. This rescission was very tangible from the mean difference between C1 and C2 score averages.