It is often said that the first impression is the most important in forming an opinion of a person. In some ways, this is similar to how the early moments of a lecture can mould students' interest and dictate its overall success. With regards to teaching life sciences, the underlying objective is obviously not merely downloading information to the recipients but rather, to inspire students to learn independently on their own beyond their brief encounters with us. Thus, the challenge is to figure out how to generate suffi cient interest in students to fuel their passion for sustainable self-directed learning in the early formative moments of a lecture.

Through a number of unfruitful attempts in importing teaching styles which I have acquired abroad, I was rudely awakened by the fact that learning styles are highly dependent on the cultural context. By this I mean how an individual learns is shaped largely by one's learning environment rather than one's innate intelligence. By understanding the cultural context, it is possible to incite students' passion in a subject like the life sciences which require the acquisition of mammoth amount of information and turning it into useful knowledge later on.

Let us start by asking the question: "What makes a good lecture or seminar"? The answer often lies in how the presentation is conducted and how the speaker relates to the audience. If a lecturer starts in a mundane fashion or seems unprepared, it will take sometime to build up a momentum suffi cient to capture the audience's attention. Thus, with restricted amount of contact time, the lecturer may not be able to develop the required momentum. Had the same lecturer started by engaging the audience in an interactive fashion using suitable presentation styles and ending with poignant issues for further ruminations, there is a good chance that the lecture will go well. I will illustrate this by using some examples from my lectures.

In both undergraduate and graduate studies, the common challenge is to find ways to encourage students to learn to discuss, search for information and conceptualise ideas in biology. The first few moments of a lecture can serve to capture students' attention and thereafter, moulding their minds becomes easier. To set the stage, I usually start with a simple practical demonstration where I will be the centre of attention. This can be intimidating initially. The key is to be mentally prepared before the class begins regardless of its size or level. One thing I never do is to dismiss the importance of being mentally prepared even if I had delivered the same material umpteen times.

In an undergraduate class of more than 300, the practical demonstration illustrates how a genetic material called deoxyribonucleic acid (DNA) can be easily isolated from a solution. Students are often fascinated as they have heard about DNA in high-schools but yet have little knowledge of what a piece of dried form of DNA feels like or how DNA can be spooled from a solution. This demonstration serves another purpose-to bridge the communication gap between students and me. I will ask students to offer explanations on their observations of how DNA precipitates. As with most Asians, NUS students are often reserved and do not interact well with the lecturer.

I then draw students out of their cocoon by selecting students to attempt the question. This is not an easy task especially with our first year undergraduates (freshmen) who are usually unaccustomed to interaction in a large class for fear of being belittled by fellow students. It is our duty as lecturers to dispel such fears that will invariably impede students' self-confidence-a prerequisite for self-directed learning. Frequently, students provide wrong explanations. These can serve as opportunities for interaction and allow me to hit home the message that we are here to learn and it is permissible to make mistakes. Communicating to students that it is alright to make mistakes has a profound effect on some students and can be the start of bridging the gap between them and us. It is important not to belittle those who have provided the wrong answers and to distinctively compliment those who have given the correct answers. On occasions, I will pose questions which do not have clear-cut answers. These questions inevitably draw students to offer possible explanations and allow students to learn how hypotheses can be formulated and how experiments are designed to test the hypotheses. These early interactive formative periods thus lay down the 'rules of engagement' and erode the barrier between the 'almightyknow- it-all' professor and students. Very soon, students will know that lectures are not a unidirectional didactic delivery of information but sessions that endorse bantering and the active exchange of ideas.

In our attempts to demystify and de-convolute complex concepts in biology, some thoughts should be given to presentation styles. Firstly, presentations must be sufficiently engaging and interesting so that students will be inspired to find out more by themselves. Most of my presentations include virtual animations to illustrate the 3-dimensional aspect of the molecules under discussion. I also use physical objects to illustrate the concepts when students have diffi culties visualising the animations. An example is the illustration of the planar nature of peptide bonds and steric hindrance of large bulky side groups. Here, two sheets of cardboards are used to show that there is a defi ned angle that the two planes can rotate, hence restricting the angle of the bonds.

By establishing an interactive atmosphere early on in the lecture, we set the stage for students to discover the fascinating world of life sciences through self-exploration.