第2章計算論的思考と設計の再利用性

In today’s technology world, mastering computational thinking techniques is important. These techniques offer a systematic way to solve problems using tools like data structures, which are like containers used to organize and store data efficiently in a computer. They define how data is logically arranged and manipulated, making it easier to access and work with information in algorithms and programs. There are four key techniques (cornerstones) to computational thinking, as illustrated in Figure 2.4:

• Decomposition is a fundamental concept in computational thinking, representing the process of systematically breaking down a complex problem or system into smaller, more manageable parts or subproblems. By breaking down complexity into simpler elements, decomposition promotes a more organized approach to problem-solving.

• Logical thinking and pattern recognition is a computational thinking technique that involves the process of identifying similarities among and within problems. This computational thinking technique emphasizes the ability to recognize recurring structures, relationships, or sequences in various problem-solving situations.

• Abstraction is a computational thinking technique that centers on focusing on important information while ignoring irrelevant details. This technique enables a clearer understanding of the core issues.

• Algorithms are like detailed sets of instructions for solving a problem step-by-step. They help break down complex tasks into manageable actions, ensuring a clear path to problem-solving.

In addition to the four techniques, computational thinking involves essential steps such as testing and debugging. Testing is crucial for uncovering errors within the step-by-step instructions or algorithms employed to tackle a problem. On the other hand, debugging entails identifying and rectifying issues within the code.

A programmer is someone who writes instructions for a computer to follow. A typical example is that of a programmer who gives instructions to a robot and tells it to make a jam sandwich. In this case, applying computational techniques to give instructions to the robot entails the following techniques: decomposition, logical thinking and pattern recognition, abstraction, and algorithms. These techniques are explained in the following subsections as they apply to the jam sandwich example.

Analyzing data involves collecting and cleaning information, exploring patterns through visual and statistical methods, and forming hypotheses. Statistical analysis and visualization are used to draw conclusions, and findings are interpreted and communicated in reports or presentations to help in the process of decision-making. Analyze the patterns and trends in traffic accident data to understand the prevalence of road injuries and fatalities, and examine the progression of traffic incidents over time. To enhance road safety measures and policies, you should apply computational thinking skills to identify recurring patterns and abstract the most crucial information from the data. By extracting valuable insights, you can contribute to the development and refinement of strategies that effectively improve road safety.

Decomposition involves solving a complex problem by breaking it up into smaller, more manageable tasks. Decomposition enables the consideration of various components essential for solving a seemingly complex task, allowing it to be redefined into a more manageable problem. In the case of the jam sandwich example, decomposition involves identifying all the required ingredients and the steps the robot must take to successfully create a jam sandwich.

Pattern recognition makes it possible to group all the different features considered in decomposition into categories. In the jam sandwich example, pattern recognition leads to grouping the various things identified via decomposition into categories, in this case, ingredients, equipment, and actions. Therefore, applying decomposition and pattern recognition will lead to thinking of as many things as possible that are required to make a jam sandwich. The more things that can be thought of (i.e., ingredients, equipment, and actions), the clearer the instructions will be. A first attempt at decomposition and pattern recognition is summarized in Table 2.1.

The process of identifying patterns typically requires logical thinking such as inductive or deductive reasoning. Inductive reasoning makes it possible to go from specific examples to general principles. For example, recognizing that dividing any number by 1 results in the original number leads to the broader conclusion that holds true for any number. Similarly, understanding that the sum of two odd numbers yields an even number leads to the generalization that adding two odd numbers always results in an even number. Inductive reasoning turns an observation into a pattern, which allows making a tentative hypothesis that can be turned into a theory. Deductive reasoning is the process of drawing valid conclusions from premises given the fact that it is not possible for the premises to be true and the conclusion to be false. A traditional example illustrates how the premises “all men are mortal” and “Socrates is a man” lead to the deductively correct conclusion that “Socrates is mortal.”