Teaching Methods in Computer Science Education - Guide to Teaching Computer Science: An Activity-Based Approach - page 110

In the next stage, we see that this task has the potential to raise discussions
about a wide variety of computer science topics, such as:
- Abstraction
- Programming style
- Conditional statement, different brunching strategies, linearity versus
nesting
- Imperative versus functional approach
- Efficiency
- Readability
- Procedures/methods, functions
- Meaningful names
- Boolean expressions and functions, the flag metaphor
- Data types
- Parameters
- Sophisticated (tricky) solutions
As can be easily observed, these concepts are varied and highlight both
rigid and soft aspects of computer science; therefore, such tasks, though
look relatively simple, are called rich tasks.
• Stage B: Presentation of learners' solutions
After the learners worked on the task, the solutions are presented by the
instructor and discussed with the whole class. The instructor, however,
does not set the order of presentation randomly or according to the learn-
ers' desire to present their solution; alternatively, in order to exhaust the
potential pedagogical contribution of this task, the instructor selects very
carefully the order of presentations (and even prepares it a priori). The
solutions can be presented by, for example, their readability level, their
algorithm complexity, their sophistication level, or the level of the com-
puter science ideas they demonstrate. For each solution, it is recommended
to highlight what computer science ideas it illustrates.
Table 7.5 presents possible solutions for this task. If time permits, it is sug-
gested to let the learners capture the essence of each solution by giving it a
title.
• Stage C: Class discussion
In the discussion, it is important to highlight the messages emphasized in
the introduction of the concept of rich task.
• Stage D: Construction of a rich task, homework
As homework, the learners are asked to construct another rich task and to
explain the guidelines they followed. It is important to note that it is not
a simple task to construct a rich task. In fact, the construction of a rich
task is a kind of a rich task by itself since it requires the consideration of
different options and the exploration of the computer science ideas that can
be expressed by the possible different solutions of the task.
We present one additional example of a rich task: Write a function that
returns the maximum of four given numbers.