H C I

UNIT I Human Computer Interaction

1. Foundations of HCI

Human-Computer Interaction (HCI) focuses on the design and use of computer technology, especially the interaction between humans (users) and computers. Key concepts include:

  • The Human: Input/Output channels, Memory, Reasoning and Problem Solving.

  • The Computer: Hardware devices, Memory, Processing, and Networks.

  • Interaction: Models, Frameworks, Ergonomics, Interaction styles, and Elements.

1.1 Introduction

HCI involves observing how people interact with computers and designing technology that allows for effective human-computer interaction. Factors include sensory perception (sight, hearing, touch) and the various definitions of a user, whether as an individual or group.

1.2 Goals of HCI

The goals of HCI include:

  • Creating usable and safe computer systems.

  • Ensuring that users' needs, capabilities, and preferences direct system design.

1.3 Usability

Usability is vital in HCI and encompasses how easily users can learn and interact with a system. Key attributes include:

  • Easy to learn

  • Easy to remember

  • Effective and efficient use

  • Safe and enjoyable to use

1.4 Factors in HCI

Several factors must be evaluated during design:

  • Organizational Factors: Training, job design, roles.

  • Environmental Factors: Noise, lighting.

  • Health and Safety Factors: User cognitive processes and ergonomic considerations.

1.5 Disciplines Contributing to HCI

HCI draws from various fields:

  • Computer Science: Software design.

  • Cognitive Psychology: Understanding cognitive limitations.

  • Ergonomics: Design for readability and usability.

1.6 Input-Output Channels

Interactions between users and computers involve input (via senses) and output (via actions). The major senses involved in HCI are vision, hearing, and touch. Each plays a significant role in user interaction and feedback.

1.7 Cognitive Models of HCI

Cognitive models help in understanding user behavior. They can be task-oriented (hierarchical models) or represent the user-system grammar (linguistic models). GOMS (Goals, Operators, Methods, Selection) model is one of the prevalent cognitive models used.

2 UNIT II Design & Software Process

2.1 Interaction Design Basics

Interaction design creates specific stages and requires iterative processes to accommodate user needs and constraints. Key steps include:

  • Understanding users and their context.

  • Employing scenarios that illustrate user interactions.

2.2 Prototyping and Evaluation

Prototyping is essential for refining designs:

  • Throwaway Prototyping: Discarding after use for feedback.

  • Incremental Prototyping: Building the system in stages.

  • Evolutionary Prototyping: Continuous improvement on the same design.

2.3 Usability Engineering

Usability engineering emphasizes metrics that gauge a product's usability through methods that include observational studies and performance testing.

3 UNIT III Models and Theories

3.1 Cognitive Models

Cognitive models represent users and include:

  • Hierarchical Models: Show goal and task structure.

  • Linguistic Models: User-system interactions as language.

3.2 Socio-Organizational Issues

Recognizing organizational dynamics, such as power relationships and stakeholder motivations, is crucial in HCI.

3.3 Communication and Collaboration Models

Understanding human-human interaction paves the way for effective communication interfaces:

  • Face-to-Face Communication: Impact of non-verbal cues.

  • Text-Based Communication: Adaptation of face-to-face norms.

4 UNIT IV Mobile HCI

4.1 The Mobile Ecosystem

Mobile technology operates within a vast ecosystem involving operators (service providers), networks, sectors (smartphones vs. feature phones), and platforms (Android, iOS).

4.2 Design Principles for Mobile Applications

Key elements include:

  • Simplicity in the user interface

  • Adaptive layouts for varied screen sizes

  • Contextual relevance for user tasks.

4.3 User Experience in Mobile Design

Mobile interfaces need to deliver seamless interactions within limited task durations, emphasizing accessibility and simplicity.

5 UNIT V Web Interface Design

5.1 UI Design Basics

UI design includes anticipating user tasks, leveraging consistency, simplicity, and clarity. Important elements are:

  • Input Controls: Buttons, text fields.

  • Navigation Components: Menus, sliders.

5.2 Drag and Drop Interactions

Critical moments in drag and drop must be effectively communicated through visual cues and feedback mechanisms to enhance user experience.

5.3 Contextual Tools and Overlays

Incorporating tools and overlays that offer necessary functionality while maintaining user context ensures a more fluid interaction.