At the Department of Computer Science, some of the undergraduate courses have large student enrolments. This is especially so for the lower level undergraduate courses. Lecturing to a large class poses some challenges. Typically, there is limited student interaction during each lecture. Consequently, how to increase student participation during lectures in order to facilitate teacher-student and student-student interaction becomes an important issue.

In this short article, I will share my experience in a classroom experiment conducted with the aim of increasing student participation. The experiment took place during Semester 2 of Academic Year 2002/03. The class involved had more than 170 students, mostly second-year undergraduates majoring in computer science. The course covered introductory artificial intelligence.

Ingredients of the experiment

One way to increase student participation is for the teacher to pose questions to the students. The hope is that students will be forced to think and reason when faced with questions, and that answering the questions gives them an opportunity to interact with the teacher. However, this approach of posing questions may not work well in practice. Lecturers and students are all too familiar with the situation when a question posed is met with deafening silence. Even after repeated prompting, students are still too shy to volunteer to answer the question. A better way to encourage students to speak up is needed.

In my experiment, after I posed the question, I first got the students to discuss in groups of two (i.e. each student discussed the question with his/her neighbour seated next to him/her) for two minutes. This serves as an icebreaker, since students are generally less inhibited when they engage in small-group discussions. It also achieves the aim of increasing student-to-student interaction during the lecture.

In order to challenge the students to engage in higher-order thinking, a question that leads the students to relate different parts of the course material and to ‘see the big picture’ is preferable, instead of a question that asks them to regurgitate facts. In the experiment, the lecture topic was on machine learning. The question I asked was: “Give an algorithm to generate a good decision tree that maps an example to a category, given a set of examples with assigned categories.”

At the point of posing this question, I had not touched on any learning algorithms. However, earlier topics of the course covered include search, representation and inference, and planning. It was pointed out to the students before that both inference and planning could be viewed as a search procedure. Hence, a deep understanding of these previous topics would enable a student to come up with an answer to the question posed (i.e. a search algorithm that views learning as search).

Another aspect of increasing class participation is to engage students in a discussion, instead of a one-way process of posing a question and getting an answer back. This can be brought about by asking sub-questions whose answers then lead to more subsequent questions. In this way, the teacher can provide hints and build upon the students’ partial answers, and foster an interactive discussion in the process.

Outcome of the experiment

After warming up by discussing with their fellow students first, the students were less inhibited in answering the question. After some hints and prompting, one student was able to come up with the correct answer. In the process, another student even asked me to clarify a point.

Overall, the outcome of this experiment is that the students did develop a deeper understanding of the connection between the different parts of the course material. The students became more active in class participation, not only in answering the question, but also volunteering to ask a related clarification question about the topic. The classroom atmosphere became livelier as a result.

Pausing a lecture to get students to first discuss among themselves a higher-order question takes up a bit more time. However, this practice does break the monotony of lecture and its occasional use brings benefits and increases student participation in a large class.