A Handbook for Teaching and Learning in Higher Education Enhancing academic and Practice

286 ❘
Teaching in the disciplines
value recorded on the Frisbee, which is returned when they reach the end of the
function call.
This simple strategy graphically illustrates the difference. An extension is to attach
a piece of string to each passed Frisbee so that a swift tug can precipitate the
return; this provides a further neat illustration of pointers!
Data structures
When they have mastered the basics of programming, students often move on
to implementing simple data structures such as linked lists or stacks. A significant
part of the battle in teaching these structures is to explain to the students
what such a structure is and how pointers are usually used to implement
and eventually traverse one. The students in a lecture room can be turned into a
linked list. One student is nominated as the head of the list (effectively a pointer
to the first item) and is equipped with a large ball of wool. The student throws
this to another in the room, who forms the second element, and so on. When
a suitable structure has been created, the instructor can show how to traverse
the list to find certain values, and can show how it is vital not to lose the first
element.
It is straightforward to extend this idea to explain more complex operations with
these structures, such as the deletion of an element. This requires some temporary
pointers (and scissors!) as the wool forming the list is cut and then tied back
together.
A word of caution
The effectiveness of these techniques lies in their novelty. Lectures using ideas
such as these will hopefully be memorable, and the subject of much discussion
afterwards. That is important.
It is probably possible to devise demonstrations to illustrate most parts of an
introductory programming course, but if they are overused they can lose their
crucial novelty value.
(Dr Tony Jenkins, University of Leeds)
Teaching methods
Courses in computing provide a mix of both theory and practice, thus enabling transfer
of knowledge and the development of skills. Case study 1 highlighted the need for active
rather than passive learning. In order to involve students in active learning it is important
that they are motivated, and this is best achieved in the learning environment by ensuring