HCI 1. Introduction

Hwa Chong Institution H2 Computing 1 1 Introduction Learning Outcome Programming is a creative experience to apply computational thi nking to design the solution, and implement it in a programming language that the computer ca n understand. With the development of hardware, computers can help to solve numerous problems in an efficient way. Computational thinking is a high level problem solving skills a nd it comprises four key techniques:  Decomposition: breaking down a complex problem or system into s maller, more manageable parts  Pattern Recognition: looking for similarities among and within problems  Abstraction: focusing on the important information only, ignoring irrelevant details  Algorithms: developing a step-by- step solution to the problem, or the rules to follow to solve the problem Furthermore, we also need to learn communication skills to understand the problem and explain the solution clearly. Let’s start with a simple example as an i llustration of the complete procedure to solve a real-life problem. We will follow the six steps below to solve the problem: 1. Define the problem 2. Analyze the problem 3. Design the solution 4. Implement the solution 5. Test the solution 6. Document the solution Algorithmic Representation  Use appropriate techniques or tools such as pseudo-code and flowchart to show program flow  Use standard flowchart symbols  Use a combination of various control structures  Use decision tables to explore the actions for combinations of different input conditions  Use modular design to decompose a problem into smaller problems Data Validation and Program Testing  Explain the difference between data validation and data verification   Understand data validation techniques such as range check, format check, length check, presence check, check digit   Identify, explain and correct syntax, logic and runtime errors   Design appropriate test cases using normal, abnormal and extrem e data for testing and debugging programs

Hwa Chong Institution H2 Computing 2 Example 1 Write a program to indicate the grade of any given integer mark based on the following grading scheme: Mark Range Grade 0 – 44 Fail 45 – 100 Pass 1.1 The First Step: Define the Problem Here, we write a statement of the objectives to be accomplished – the problem we are trying to solve. If necessary, we also specify the users of our program. 1.2 The Second Step: Analyze the Problem Here, we identify the following: (a) values that must be supplied from outside the program (input data) (b) values that are given on the problem (constant data) (c) values that must be produced as a result of solving the problem (output) Effectively, the first two steps focus on what the program must achieve. For Example 1, we have input data of a positive integer Mark, constant data of 0, 44, 45, 100, and the output data is ‘Fail’ or ‘Pass’.