Evaluation of the effects of medium of instruction on the science learning of Hong Kong secondary students: Performance on the science achievement test

Bilingual Research Journal, Summer 2003 by Yip, Din Yan, Tsang, Wing Kwong, Cheung, Sin Pui

The quantitative part of this study was complemented by a student questionnaire eliciting their self-concepts and feelings of competence in science. This gave us some indication of students' psychological development. The questionnaire also explored the classroom climate. In addition, we observed science lessons for a small number of schools selected from the EMI, CHIG, and CMID strata. The CLOW schools were excluded from the lesson observation exercise because the students at these schools tend to have a poor attitude toward learning, and there are more serious classroom management problems that may interfere with the comparison of MOI effects. [The qualitative part of the study, i.e., lesson analysis, will be presented in a separate paper.] Some lessons were videotaped for further analysis. The information collected from questionnaires and from classroom observations regarding classroom climate provided some insights into the effects of the MOI on the differential science achievement of the EMI and CMI students.

Compared with previous local studies on the effects of MOI on science learning, the present study is more systematically and vigorously designed. Its methodology has the following strengths:

1. The project involved a longitudinal study of a large representative sample.

2. The differences in prior achievement of individual students, in terms of the AAI, and other student variables were controlled.

3. The use of multilevel modeling technique allowed better differentiation of the effects of individual students and schools than the multiple regression analyses used in many of the previous studies.

4. As no mixed-code teaching is allowed in the new language policy, the effects of the MOI on student learning can be identified more accurately. Interviews with teachers and students indicate that since the implementation of the new policy, mixed code is generally not practiced in science lessons, though occasionally teachers may use Chinese to supplement their English explanations when teaching difficult or abstract concepts.

5. The new policy ensures that most students in EMI schools have reached a threshold level of English proficiency (based on conclusions drawn from previous research, e.g., Brimer et al., 1985; Education Commission, 1990). This allows for a more valid evaluation of the effects of late-immersion programs on the development of additive bilingualism and acquisition of subject contents.

Focus of the Present Paper

This paper will be the first of a series of publications on the results of the study of the effects of the MOI policy on science learning in Hong Kong. It will focus on the performance of the 1999 cohort of students on the S2 Science Achievement Test (SAT) conducted in April through June 2001. The data analysis includes: (a) multiple comparison of the mean performance on the S2 SAT among the four school strata (i.e., EMI, CHIG, CMID, and CLOW); (b) multilevel analysis of factors affecting students' science achievement in S2; and (c) item analysis of students' performance on individual multiple-choice and free-response questions of the EMI and CHIG strata.