Problem-Solving Strategies - Guide to Teaching Computer Science: An Activity-Based Approach - page 81

The importance of the stepwise refinements process increases as the problem com-
plexity elevates. But, as it turns out, it is also useful for solving basic problems, such
as finding the maximum of three numbers, as is discussed, for example, in Reynolds
et al. ( 1992 ).
Activities 35 and 36 focus on stepwise refinement.
Activity 35: Practicing Stepwise Refinement—Break-Down Problem Solutions
into Subtasks
The students continue working on the problems they developed in Activity
31, and are asked to break down the problem solutions into subtasks.
Activity 36: Practicing Stepwise Refinement—Analyze a List of Problems
The students receive a list of problems and are asked to analyze them compre-
hensively, considering inputs-outputs categories, variable selection, and the
implementation of stepwise refinements.
Learning from an expert as an apprentice approach is very well appreciated in many
professions (e.g., architecture, music). Based on the premise that in reality problem-
solving skills are developed through experiencing and practicing over a period of
time, Arshad ( 2009 ) presents a pedagogical approach to teach problem solving by
using the thinking-aloud strategy. Specifically, students learn the skill of problem
solving by closely observing and listening to an “experienced programmer”. The
evidence show that think-aloud problem solving is extremely effective for female
students. These research findings probably correspond with the personal experience
of each programmer. A quite frequent scenario is in which one receives a logical
problem defined in terms of an algorithm or a program, and while explaining the
problem-solving approach (either to a classmate or to an educator or an educator
explains to one of his or her students), he or she finds the solution. Activity 37aims
at highlighting the potential of the think-aloud problem-solving strategy and prac-
ticing it in a structured manner.
Activity 37: Practicing Think-Aloud Problem Solving
The target of this activity is to enrich students' considerations while solving
a problem by listening to a peer who solves the same problem (specifically,
with MTCS classmates, or, in the case of a programming-oriented course,
with classmates or a two students from different academic years).