Abstract:

In 2009, the Japanese government launched an initiative for facilitating Japanese universities to promote English-medium instruction. We started the OnCAL (Online Corpus of Academic Lectures) project with the purpose of supporting instructors who are non-native speakers of English (NNS) in their preparation for delivering lectures through English. OnCAL is a database of 430 transcriptions of lectures on basic science (mathematics, chemistry, physics, biology) courses which were downloaded from MIT OCW (MIT Opencourseware) and also applied science or engineering (advanced mathematics, artificial intelligence, robotics) courses which were downloaded from SEE (Stanford Engineering Everywhere). OnCAL has been updated various times, and in its present form offers many examples of how a specific pedagogical purpose is realized in science and engineering lectures by instructors who are native and near-native speakers of English (NS). In this work, we focus on a concrete pedagogical purpose, that of explaining mathematical formula, because we suppose that NNS instructors may face challenges when having to explain in the classroom how a mathematical formula is derived, expanded, etc. A typical situation where mathematical formulas have to be explained in detail is when specific conditions allow approximations and simplifications of the formula for a general case. The expression "when x is negative, the signum of x is minus one, so..." is a simple example showing how a formula changes form under a specific condition. This type of pedagogical discourse has some interesting features. First, it is usually used in parallel with other modes like blackboard writing or other visuals. In addition, it may extend over many minutes and occupy a large portion of a lecture (depending on the field and the topic treated in the lecture); in this case, the discourse contains many different types of expressions. Finally, this type of discourse relies heavily on the accuracy of the spoken language used. We believe that explaining mathematical formula accurately is of primary importance in science and engineering lectures, and that OnCAL can offer many examples of how this pedagogical purpose is realized in lectures. The examples we located are numerous and can hopefully cover most of the concrete needs of NNS instructors. They can then learn the patterns and apply the knowledge in their concrete cases. We therefore propose that NNS science instructors (or even less experienced NS science instructors) can use OnCAL to obtain insights into their pedagogical discourse needs for effective teaching. Furthermore, we realized more recently that OnCAL is meaningful also to NNS students (or even NS students) because they can improve their lecture comprehension skills by using OnCAL as a source of lecture samples that allows them to learn many expressions that signal a specific pedagogical function.

Keywords:

English-medium pedagogy, science education, classroom discourse.