I believe that the principal role of a “teacher” is to help a student increase his or her awareness of a subject. This increased awareness can be in the form of a broadening of the student’s knowledge into entirely new and foreign areas of study. In other instances this increased awareness can be in the form of a deeper understanding of a particular subject that the student has prior familiarity. I often explain to students that I view the role of a teacher as being analogous to a mountaineering guide. In introductory courses, the role of this guide is to bring the students along on a trip into a beautiful alpine valley and point out the interesting scenery. More importantly, the guide should point out where the student should return with climbing equipment for further investigation. In more advanced courses, the guide is there to provide the necessary tools to help the student climb the more difficult peaks. It is in the advanced courses where the teacher should strive for completeness in their coverage of material. This completeness is to ensure that the student has a good understanding of the subject. The students newly acquired knowledge can then be put to practical use or serve as a good foundation for more advanced studies in that field. At the same time, the teacher should strive for conciseness and clarity to convey the knowledge in a manner as efficient as possible.

Often, the first task of the teacher is to motivate the student’s interest in the subject matter. This is done by showing the importance of the particular material to other fields of knowledge that is of interest to the student. Another role of the teacher is to facilitate the acquisition of new knowledge by the student by providing a link to knowledge that the student already possesses. One of the more challenging aspects of teaching that I have encountered is the wide spectrum of student backgrounds that can be encountered in a course. I have taught several courses attended by both graduate and undergraduate students. It is particularly important in these courses to gauge the varying backgrounds of the students and make accommodations. To do this, one must become familiar with the background and needs of the students. Interacting with the students and obtaining feedback from them develop this familiarity.
The choice of teaching tools is very important and must be made wisely. I believe that visualization of the material being covered facilitates learning. Whenever possible, I incorporate visual aids into lectures. Demonstration is often the best means of teaching. There is nothing like a loud bang to get the attention of students. I have also sought to incorporate the use of computer aided instruction tools into my courses. For instance, the course in observational astronomy that I have taught uses software that simulates astronomical observatory equipment to obtain simulated data that can be analyzed by the student. In this course, students were able to perform measurements of the mass of Jupiter and the age of the Universe by using these software tools. In the optics course, I have used Java applets to demonstrate various principles of optics. The students could then “play” with the demonstrations to get a “feel” for the systems being studied. However, sometimes just working through example problems on a blackboard is the best tool for instruction.

In laboratory courses especially, another important role of a teacher is to provide proper guidance. This guidance mainly consists of the ability to identify that which the student is having difficulty understanding. The teacher can also be helpful in pointing out to the student what are the important elements in a subject. In all courses, providing quick feedback to the students in some form, such as graded homework, exams and/or lab reports, is often very important to the learning process of a student.

Ideally, the teacher should seek to serve as a “mentor” to the student. In the case of supervising research students this role of mentor can be realized. In this teaching role there is sufficient interaction between student and teacher that there is continuous feedback that allows the “teacher” to ensure that the student is developing a “complete” understanding of the material being studied.