Using Piaget's perspective of individual cognition and Vygotsky's theory of social constructivism as lenses, this paper reports on the instructional prompts that are used by biology lecturers to promote student interaction. The study further reports on the link between the prompts used and the subsequent quality of the interaction. Three lecturers were observed teaching third- and fourth-year pre-service teachers at a university. The first author used an observation schedule to describe what was observed in detail. Observational data and vignettes were coded for instructional prompts, and the codes were categorised subsequently. This study found that lecturers used a variety of formats of instructional prompts including the use of teaching and learning aids, teaching strategies, teaching procedures and teaching and learning activities to foster interaction. The study also found that, while the quality of the interaction could be dependent on the use of a particular type of instructional prompt (like the novel stories used in this study), it was also dependent on how the lecturer facilitated the interaction. An interesting finding that came out of this study is that allowing for cognitive interaction before social interaction enhanced the quality of student interaction in terms of engagement for learning. The study recommends that lecturers should allow students to first interact cognitively (using tools such as a worksheet) to allow for restructuring of their thinking that would then be showcased in the social interaction.