Software Engineering Life Cycle and Usability Design

Software Engineering

Discipline for understanding software design processes.

Usability Design

Occurs at all life cycle stages, not isolated.

Requirements Specification

Captures expected system functionalities in various languages.

Architectural Design

High-level description of system components and relations.

Detailed Design

Refinement of components to identify separate modules.

Verification

Ensuring the product is designed correctly.

Validation

Ensuring the right product is designed.

Formality Gap

Validation relies on subjective proof methods.

Usability Engineering

Specifies usability measures as explicit requirements.

Effectiveness

Ability to achieve desired outcomes.

Efficiency

Completing tasks without wasting effort.

Satisfaction

Enjoyment of the process of using the system.

Iterative Design

Addresses incomplete requirements through repeated cycles.

Prototypes

Simulate features of intended systems.

Throw-away Prototypes

Prototypes discarded after initial testing.

Incremental Prototypes

Builds system in small, manageable increments.

Evolutionary Prototypes

Refines prototypes through continuous feedback.

Storyboards

Visual representations of user interactions, not always digital.

Limited Functionality Simulations

Partial system functionality demonstrated by designers.

Design Inertia

Early poor decisions persist throughout the design.

Design Rationale

Explains reasons behind system design choices.

Issue-Based Information System (IBIS)

Framework for design rationale research.

Design Space Analysis

Evaluates design options using structured questions.

Decision Representation Language (DRL)

Formal semantics for decision-making in design.

Psychological Design Rationale

Links user tasks with system design consequences.