Human-Computer Interaction
HCI Lifecycle Overview
and Initial Analyses
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Lecture Overview
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Overview of interactive system design
Development team roles
Problem statement
Systems analysis + HCI perspective
User analysis
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Fundamental Activities of
Interactive System Design
• Information gathering and model building
• Synthesis (or enhancement) of a solution
• Analysis (or evaluation) of a solution
These activities are iterated
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Microsoft: Activity Based Planning
- Ref MS Office 97
• Listening to and understanding users
• Observing how they work with software and what
tasks they perform
• Coming up with features to address these work
styles and tasks
• Testing the features with the people that actually
use them
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User Object Modelling
System Design Spec. (inc. Interface Design Dpec.)
User’s Conceptual Model Design / Interaction Style
Interaction Design / Presentation Design
Design
U s e r P a r t i ci p a t i o n
Requirements Spec. (inc. Usability Specs.)
Analysis
Systems Analysis (incl. User and Task Analysis)
Definition
Problem Statement
Prototype (inc. Context Sensitive Help)
Evaluation (Analytical, Empirical)
Implementation
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Balance Among Conceptual, Interaction
& Presentation Design Effort
Detailed
Design
Presentation (‘Look’)
10%
– Visual representations
– Aesthetics
Interaction (‘Feel’)
30%
– Interaction Techniques
– Standard Menus
Conceptual Design
60%
Design
Proceeds
‘Mainly’
From The
Bottom
Level Up
Metaphors, Object
Attributes, Relationships,
Behaviours
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Definition of Design
“ . . . the use of
scientific principles,
technical information
and imagination.”
Feilden Committee Report, 1963
Engineering Design, HMSO
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Roles in a Team for Interactive
System Development
User
(domain
expert)
Team
User
interaction
developer
User interface
software
developer
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Problem Statement
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Supported activity
Users
Level of support to be provided
Form of solution
• Statement of overall goal of whole system in a
single phrase or sentence
• Aim: show clear understanding of what is needed
• Main assumptions should be separately stated
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Problem Statement: Example for
Diary Management System
• Supported activity
• Maintain appointments
• Users
• White collar customers
• Level of support to be provided
• Appointment (an object)
• Maintain (an operation)
• Add, modify, delete, view appointments
• Adjust alarm
• Form of solution
• Portable hardware, low selling price
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Systems Analysis + HCI Perspective
• Systems analysis
• Identify entities of significance to the ‘system’
• Functionally oriented and data driven
• Design notation
• e.g. Data flow diagrams, Entity-Relationship diagrams
• Often met with resistance by users
• HCI perspective
• Identifies issues of practical effectiveness
• Usability orientation • e.g. speed, error rates
• Design notation
• Designed to be understood by users e.g. task hierarchy
diagram, screen sketch
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Perspectives in Tension
• Systems analysis and software implementation
• Logical flow of data
• Computational efficiency
• Ease of development
• HCI
• Quality of user interface
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Conventional + HCI Data Gathering
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Read background material
Guided tour of work environment
Interviews
Observation
Questionnaires
Forms analysis
Verbal protocol
Tape / Video recording / Transcript
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User Analysis
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Expertise level (novice, intermittent, frequent)
Familiarity with specific hardware and software
Software with which users are familiar
Job-related information access needs
• E.g. summary vs detailed
• Skill base e.g. typing
• General educational level
• Organization-specific knowledge and/or
experience
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User Analysis: Example for Diary
Management System
• User characteristics
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Professional, white collar
Keeps schedule for self and/or others
Sometimes just for personal use
Keeping diary is a very small part of user’s job
• Skills
• High general skill level
• Not necessarily computer skilled
• Not all will have keyboard skills
• Conclusions
• Keep it simple
• Functionality and usability greater than for paper diary
• Minimize typing, and be quick and easy to learn
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Lecture Review
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Overview of interactive system design
Development team roles
Problem statement
Systems analysis + HCI perspective
User analysis
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