HCI in Software Development Process

HCI in the Software Process

• The goal is to create effective, user-friendly interactive systems, moving beyond simply identifying design paradigms to examining the entire interactive system design process. Integration of user-centered design within broader software development is key.
• Software engineering, as a computer science field, manages technical and managerial aspects of software development using the software life cycle. This cycle encompasses everything from initial concept to eventual retirement.
• HCI considerations are integral throughout the software life cycle, rather than as a separate, isolated activity.

Introduction

• Creating effective and user-friendly interactive systems requires reliable methods, and integrating user-centered design is crucial within the context of software development frameworks.
• In software engineering, software life cycles (from inception to removal) manage the technical and managerial aspects of development.
• Customer needs and roles, as well as end-user roles, must be distinguished in software development: the customer commissions the design, the end user uses it.

The Software Life Cycle

• A fundamental feature of software engineering is structured application of techniques using the software lifecycle.
• The software life cycle defines development activities that must be ordered in time within any project.
• In software development, two main roles are the customer and the designer, with customers commissioning and designers creating the software. These roles might sometimes be filled by the same individual.

Activities in the Life Cycle

• The software development life cycle activities, often likened to a waterfall model, are:
  • Requirements specification
  • Architectural design
  • Detailed design
  • Coding and unit testing
  • Integration and testing
  • Maintenance

Verification

• Verification ensures a system meets stated requirements and specifications correctly.
• It is a process of evaluating software to ensure it is being correctly built in accordance to its design requirements.
• The purpose of verification is to ensure that the system adheres to its specifications and design documents and to identify issues early in the design process.
• Questions answered by verification include: are we building the system right?, does the system meet design requirements?

Validation

• Validation assesses whether the software meets end-user needs and expectations.
• It ensures that the software works correctly in the real world and performs intended functions.
• The purpose of validation is to ensure that the software satisfies user needs and works in the intended real-world scenarios and to verify the system meets its intended purpose and adds value to users.
• Questions answered by validation include: are we building the right system?, does the system meet user needs?

Usability Engineering

• Usability engineering introduces specific usability standards and criteria to evaluate a product's usability in a user-centered design approach.
• Usability engineering focuses on understanding how usability affects a user's experience with the product, including the interface and its overall architecture.
• Usability specifications are integrated into the requirements specification, outlining six relevant attributes to evaluate product usability.

ISO Usability Standard 9241

• The ISO standard defines effectiveness, efficiency, and satisfaction as key categories used for evaluating usability.
• Effectiveness: can users perform their tasks or goals?
• Efficiency: how much effort is required when completing a task?
• Satisfaction: are users happy with their use experience?

Problems with Usability Engineering

• Usability metrics are often tied to specific user actions in specific contexts and may not be available at the design phase.
• Ensuring compliance with usability specifications doesn't guarantee overall usability or address root causes of usability problems.
• Designers need to understand how usability metrics translate to positive, genuine user experience.

Iterative Design and Prototyping

• Requirements for interactive systems often need refinement and are rarely fully defined at the start.
• Iterative design method uses repeated prototyping and testing to refine designs with feedback from users. The approach uses iterative feedback cycles to enhance designs.
  • Iterative design emphasizes development issues.
• Techniques for prototyping include throw-away prototypes, incremental prototypes, and evolutionary prototypes.

Techniques for Prototyping

• Storyboards: visual tools showing interaction sequences, helpful in illustrating user flows.
• Limited functionality simulations: basic non-interactive versions for testing core concepts.
• High-level programming prototypes: more functional prototypes closer to the final product offering extensive testing possibilities.

Design Rationale

• Design rationale explains the reasoning behind design decisions, essential for transparency, justifying decisions and clear communication among stakeholders.
• The rationale should highlight decision-making processes during a system's lifecycle.
• Well-documented design rationale leads to clearer understanding, better justification, and is beneficial for future reference and troubleshooting.

Importance of Design Rationale

• Design rationale enhances clarity and understanding of design decisions.
• It aids in justifying choices and provides future reference for related projects.
• Design rationale encourages consistency in design decisions aligned with the project's goals.
• Design rationale aids in detecting and resolving design issues.

Examples of Design Rationale

• User interface design rationale explains the reasons behind layout choices that were favored by user feedback and intuitive navigation.
• Rationale for system architecture choices includes scalability, maintainability and deployment considerations.

Process-Oriented Design Rationale Methods

• IBIS (Issue-Based Information System): a method for structuring discussions around a central issue, with options and arguments presented within a hierarchical structure, and using graphical or textual IBIS diagrams to show relationships.
• Variations of IBIS often include more design artifacts or enhanced vocabularies and can be integrated into CAD tools for feedback.
• Overall, IBIS methods organize design processes by detailing discussions, decisions, and related linkages for different projects.

Design Space Analysis

• Aims to analyze design choices after the initial decision-making process.
• Uses a questions, options, and criteria (QOC) notation method and is helpful for highlighting different options and design decisions.
• The QOC method helps in identifying and defining specific issues in design spaces and offers an organizational framework to describe and evaluate options.

Psychological Design Rationale

• Focuses on understanding psychological aspects of how a product aligns with user tasks and motivations. It helps to predict and evaluate a system's implications in real-world scenarios.
• Task-Artifact cycles: emphasize that systems should initially be designed based on current user tasks and possible new user tasks for future versions and evolution. Tools, like electronic spreadsheets and word processors, are examples of tool evolution in response to user needs.
• Design rationale should clearly explain how design decisions affect user tasks and psychological outcomes, not just the designer's initial intentions.
• Important tasks, scenarios, reflection and documentation, are all crucial components in this approach for creating systems that are helpful and satisfy user needs.

This quiz explores the integration of Human-Computer Interaction (HCI) within software development life cycles. It emphasizes the importance of user-centered design and how it affects every phase of software creation from concept to retirement. Challenge your understanding of effective interactive system design!