Question

Write a top-down design for the following tasks. a. Finding a telephone number in the phone book b. Finding a telephone number on the Internet c. Finding a telephone number on a scrap of paper that you have lost d. Describe the differences among these designs.

Short answer

Each task requires a unique approach: phone book by listing, internet by keywords, and lost paper by searching physical locations.

Step-by-step solution

Top-Down Design for Finding a Telephone Number in the Phone Book

1. Start by locating the physical phone book in your environment. 2. Open the phone book to the alphabetical listing section. 3. Use the initial letter of the last name of the person or business to quickly narrow down to a specific section. 4. Scan through the names using the first name and then last name or business name to locate the exact entry. 5. Record the telephone number associated with the entry found.

Top-Down Design for Finding a Telephone Number on the Internet

1. Use an internet-connected device such as a computer or smartphone. 2. Open a web browser and navigate to a search engine like Google. 3. Enter keywords like the person's name or business name you're looking for, optionally including keywords like 'phone number' or 'contact'. 4. Review the search results for relevant links or directory entries. 5. Click on the most promising link and locate the telephone number if available on the webpage. 6. Record the telephone number provided.

Top-Down Design for Finding a Telephone Number on a Lost Scrap of Paper

1. Identify the last known location where you had the scrap of paper. 2. Systematically search the immediate area and trace your steps to revisit locations where you could have left it. 3. Check common places like desks, pockets, bags, and vehicles. 4. If the paper is found, read and record the phone number from it. 5. If not found, consider alternate sources to retrieve the number, such as asking others if they know or remember the number.

Describe the Differences Among These Designs

1. The phone book method relies on physical resources and is a systematic lookup by alphabetical order, whereas the internet method leverages digital resources and uses search algorithms to find results quickly. 2. The internet approach provides a wider search scope and may offer alternative information sources, but requires internet access, contrary to the physical independence of the phone book. 3. Searching for the scrap of paper is dependent on memory and retracing steps. It is less structured and more physically based than the other two methods, relying heavily on the chance of recollection or recovery through random search.

Key concepts

Top-Down Design

Top-Down Design is a systematic way of breaking down a problem or task into smaller, more manageable parts. This approach makes complex tasks more approachable by dividing them into logical steps. Let's think of it as zooming out to see the big picture before zooming into the details.

For example, consider finding a telephone number in the phone book as described in the exercise. The top-down design starts with the overall goal of finding the number. It then breaks down the process step-by-step: locate the phone book, open it, search alphabetically, find the entry, and finally, record the number.

Using this technique helps in avoiding confusion and ensures each part of the task is well thought out before execution. It helps you know exactly what to do at each stage and prevents one from feeling overwhelmed by the overall task. This clarity makes solving complex tasks easier.

Problem Solving

Problem solving is all about identifying solutions to specific challenges or puzzles. It involves analysis, creativity, and a logical approach. In the context of finding telephone numbers, each method described tackles the problem using different resources and techniques.

Let's look at the differences between the three designs given:

• The phone book method is structured and reliable if sorted properly, allowing a straightforward search by alphabetical order.
• Searching on the internet requires taking advantage of search engines, using specific keywords, and dealing with dynamic and varied information sources.
• Finding a number on a lost scrap of paper was very manual and memory-based, involving retracing steps and systematic searching of physical places.

Understanding the problem-solving aspect is crucial. Good problem solving involves knowing which strategy or tool to apply to different situations. It teaches the importance of flexibility and adaptability in tackling real-world challenges.

Step-by-Step Solution

A step-by-step solution involves identifying each stage of a process in the order they should be executed. Breaking down the tasks into smaller sections makes it more manageable and less daunting.

For instance, finding a telephone number on the internet as laid out in the step-by-step solution provided in the exercise involves several stages. Starting from using a device, opening a search engine, and inputting search keywords, all the way to clicking on relevant links and recording the number. Each step logically flows to the next.

This method of solving problems ensures that no step is missed, reducing errors and ensuring a smoother execution of tasks. It not only helps in organizing thoughts but also in documenting processes, which can be very useful for future reference and learning.