When I began my academic career at NUS, I had neither teaching experience nor any formal training in teaching methods under my belt. Naturally, my teaching methods were shaped by past interactions with my teachers and by my own preferred learning style. My favourite teachers were those who stimulated my interest in the subject by delivering the material in a clear and organised way. As a learner, my main objective was to gain from my teachers' insights.

During my first two years as a lecturer at NUS, my teaching primarily focused on transferring knowledge to students in my class effectively. Over time, as I gained more confidence in teaching, I adjusted my syllabi and lecture notes based on my experiences and improved my teaching methodology. Participating in teaching and learning seminars/workshops organised by the CDTL also helped to hone my teaching skills. In addition, I strive to connect with all my students to make their learning experiences enjoyable and exciting, stimulate their interest in the subject, and prepare them for solving difficult technical problems. Over the years, I have designed and taught numerous modules (from 1000- to 5000- level) in the Division of Environmental Science and Engineering at NUS. These modules are mostly designed to teach students knowledge and skills relevant to the industry (e.g. identifying costeffective technological solutions to complex, multifaceted environmental problems). I have also taken the initiative to teach several key modules (e.g. Environmental Technology, Air Pollution Control, and Pollution Minimisation and Prevention) that are closely linked with one another to provide students with a broad-based education.

In this article, I will elaborate on why and how I teach and highlight the learning outcomes achieved as a result of my teaching methods.

Why I teach?

Education is important and effective teaching is the key to helping students learn the knowledge and skills they need to succeed in today's rapidly changing world. Teaching is central to my development as an academic. I enjoy working with students in an academic environment thoroughly. Like many dedicated educators, I find my job challenging and immensely rewarding as I have opportunities to inspire, nurture and assist in developing students as tomorrow's professionals. I am very proud that many of my former students have been well-placed in the industry.

How I teach

My primary objectives as an educator are to ensure that students:

• Master concepts
  
  
• Gain skills
  
  
• Learn how to learn on their own
  
  
• Develop creativity in problem-solving

I firmly believe that students need to develop healthy scientific skepticism, intellectual curiosity, critical and independent thinking skills. The teaching methods I adopt to achieve my teaching objectives depends on who I am teaching. Undergraduate students, part-time MSc students, full-time MEng/PhD students all have different needs, abilities and preferred modes of communication. As each student tunes in at a different frequency, I find it necessary to employ various strategies to appeal to learners with different learning styles (e.g. analytical, visual, oral, active, passive, individual, cooperative). I also include different kinds of assignments in my modules to cater to students' strengths and develop their critical thinking and problem-solving skills.

For each class, I always prepare more material than I can present, bearing in mind which of the material must be presented and which is optional. The dynamics of each class also determines how the optional material will be employed. Students' questions and facial expressions inform me what issues to focus on, which ones to explore more in depth, what examples to give and what stories to tell. Another way I gauge students' understanding of a topic is to ask them to respond to simple questions (e.g. Should I go on? Do I need to go over this again? Are we getting sleepy? Did this example work or do I need to provide another?) by nodding or shaking their heads. As I encourage students to interact with one another and with me in class, I believe that I have transformed myself from the 'sage on the stage' to the 'guide on the side'.

I make it a point to understand students' points of view however erroneous, before attempting to give my own. This means that when I teach, I build on students' understanding of the subject matter before I proceed to offer a broader or more conventional explanation. Students in my classes know how I teach and they have asked me to help them with other subjects!

I design assessment tasks that encourage students to consider situations using perspectives different from those they normally adopt. This helps them in their professional development. I also use a number of case studies to illustrate practical applications and implications of key concepts covered in the subject matter. Student feedback suggests that what students have learnt from my teaching materials and case studies are useful beyond the classroom.

Learning outcomes

Upon completing my modules, students will have:

• The ability to apply science and engineering concepts to solve environmental engineering problems
  
  
• The ability to work together as a team
  
  
• The ability to communicate effectively
  
  
• An understanding of the impact of engineering solutions in a global context and the role of environmental engineers today
  
  
• Recognition of the need for lifelong learning and the ability to engage in it

In summary, I design my teaching methods to meet students' needs to ensure that they will be successful in their careers upon graduation. To achieve the desired learning outcomes, I employ a variety of teaching methods to help students from diverse backgrounds learn the subject matter and its applications. I feel that it is vital that educators treat their students with respect, remembering what it is like to be on the other side of the desk. As an educator, my ultimate satisfaction does not come from students' applause or positive feedback, but rather, how students have benefited from my course and my teaching.