Programming User Interface

Jakob Nielsen's 10 Usability Heuristics

When designing a program, it is important to consider the user interface. The user interface is the part of the program that the user interacts with. It is important to make the user interface easy to use and understand. This will help the user to use the program more effectively and efficiently.

One way to make the user interface easy to use is to follow Jakob Nielsen's 10 Usability Heuristics for User Interface Design. These heuristics are a set of guidelines that can help you design a user-friendly interface. Some of the heuristics include:

• Visibility of system status
• Match between system and the real world
• User control and freedom
• Consistency and standards
• Error prevention
• Recognition rather than recall
• Flexibility and efficiency of use
• Aesthetic and minimalist design
• Help users recognize, diagnose, and recover from errors
• Help and documentation

Another important aspect of designing a program is to validate the input. This means checking that the user has entered the correct type of data. For example, if the user is asked to enter a number, the program should check that the user has entered a number and not a letter or symbol. This will help to prevent errors and make the program more robust.

One way to validate input is to use while loops. A while loop is a loop that continues to run as long as a certain condition is true. This can be used to check the user input and prompt the user to enter the correct data if the input is invalid.

Finally, it is important to lay out the program in a structured way. This will make the program easier to read and understand. One way to structure a program is to break it down into smaller parts, each of which performs a specific task. This will make the program easier to debug and maintain.

By following these guidelines, you can create a program that is easy to use, robust, and well-structured.

What you will be learning

The uploaded files provide a comprehensive guide to foundational programming concepts, emphasizing user-friendly design and structured coding practices. By studying these materials, learners will gain insights into creating programs that prioritize both functionality and user experience.

The first file, "A Simple Program," introduces the concept of creating basic programs with minimal functionality while highlighting key aspects of user interaction. It demonstrates how to write clear and jargon-free prompts, specify constraints for input data to reduce user errors, and incorporate fundamental usability heuristics. These include visibility of system status, matching the system with the real world, and recognition rather than recall. Through the example of a simple payroll calculation program, learners are introduced to identifying usability issues and implementing improvements for better user interaction.

The second file, "A Structured Program," builds on the basics by transitioning from simple to structured programming for enhanced readability and maintainability. This section introduces modular programming principles, showcasing how to design reusable validation functions for integers and floating-point numbers. Learners will also explore the use of formatted strings to create dynamic and clear user prompts and error messages. The program examples in this section demonstrate how structured design enhances usability, applying heuristics such as visibility of system status, error prevention, and recognition rather than recall. The emphasis on modular code design equips learners with the skills to write programs that are both scalable and user-friendly.

The third file, "While Loops," focuses on input validation, teaching learners how to ensure robust error prevention in their programs. By using while loops, learners will learn to validate user inputs against predefined ranges and provide immediate feedback for invalid data. The file highlights the importance of heuristics like error prevention and helping users recognize, diagnose, and recover from errors. Practical examples illustrate how while loops can be used effectively in scenarios such as payroll processing, where input validation is critical for accurate calculations.

Overall, these materials aim to equip learners with the ability to design programs that prioritize user needs and prevent errors through structured coding practices. By integrating usability heuristics with foundational programming concepts, learners will be prepared to create applications that are functional, efficient, and user-centric. These lessons provide a strong foundation for developing well-structured programs that adhere to programming standards and usability principles.

Appropriate Heuristics for an Introductory Programming Course

Nielsen’s heuristics offer a valuable framework for improving the usability of software, and several of them can be effectively integrated into an introductory programming course. These heuristics help beginners understand the importance of user-centric design while developing foundational coding skills.

• Visibility of System Status (#1): Beginners can learn to provide clear feedback to users about the current state of the program. For example, a simple message like “Data has been saved” helps users understand what has happened, reinforcing the importance of communication in program design.
• Match Between System and the Real World (#2): Students can practice using plain language and designing inputs that reflect real-world scenarios. For instance, instead of using technical terms, prompts like “Enter hours worked (5-60):” align with user expectations, making the system intuitive and relatable.
• Error Prevention (#5): Introducing input validation techniques, such as using while loops, teaches students how to prevent errors before they occur. For example, rejecting invalid values for hours worked or hourly rates ensures that only correct data is processed.
• Recognition Rather Than Recall (#6): By including detailed prompts and constraints within the user interface, students minimize the cognitive load on users. Explicit input ranges like “Value must be between 20 and 80” eliminate the need for users to remember these details.
• Help Users Recognize, Diagnose, and Recover From Errors (#9): Writing clear and constructive error messages helps students understand the importance of user guidance. For example, “The value entered must be between 5 and 60. You entered 70,” informs users of the mistake and suggests a solution.

In summary, at least five of Nielsen’s heuristics can be applied in an introductory programming course, emphasizing the value of usability alongside coding fundamentals. This approach not only equips students with technical skills but also fosters a user-centered mindset crucial for creating effective software.