Chapter 3 Reference Slide 2 of Lecture 1 Human Factors Design Most products designed without adequate consideration for human factors Focus is on technology and product amp its functions Designers consider human factors an extra expense and if human factors are addressed it is after the desi ID: 573029
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Slide1
Design & Evaluation Methods
Chapter 3
Reference Slide 2 of Lecture 1Slide2
Human Factors Design
Most products designed without adequate consideration for human factors
Focus is on technology and product & its functions
Designers consider human factors an extra expense and if human factors are addressed it is after the design is complete
Cost/Benefit analysis will normally indicate otherwiseSlide3
Human Factors in the Product Lifecycle
Maximum human factors benefits are obtained when included in the basic product design process
Human factors design should occur at many stages in the design process (see table 3.3) not at just one pointSlide4
User-Centered Design
Principles:
Early focus on user and tasks
Empirical measurement (data collected from users!)
Interactive design using prototypes, where rapid changes can be made to the interface design
Participatory design where users are directly involvedSlide5
Resources for Design Work
Data Compendiums (databases)
Human Factors Design Standards
MIL-STD-1472D
ANSI/HFES-100 VDT standard
ANSI/HFES-200 software usability standard
Human Factors Principles & Guidelines (design & placement of controls on products – no specific rules, but look at cell-phones, cameras, & DVD players)Slide6
Front-End Analysis Activities
ID end users & analyze population characteristics
ID major system functions (function & task analyses)
Determine environment for use
ID user preferences/requirements - do system functions match?
Are there any existing constraints in system design?
What are the human factors criteria for design solutions?Slide7
Conceptual Design Activities
Allocate functions to be included in the product or system design (e.g. auto focus and aperture setting will be included in design)
Supporting the conceptual design process often begins vague & becomes more specific. Design solutions are often based on previous designs with new bells and whistles. Human factors specialist will focus on improving previous designs & changes
in design. Slide8
Iterative Design & Testing
Task Analysis
Major user goals & associated activities
Tasks required to achieve goals
Conditions under which tasks are performed
Task performance results or outcomes
Information or knowledge needed to perform
Communications with others to perform tasks
Equipment needed to perform tasksSlide9
Iterative Design &
Testing (cont.)
Structured Vs Unstructured Interviews
Observation
Think Aloud Verbal Protocol
Task Performance Questioning
Representing Data with Lists, Outlines, Matrices, etc.
Hierarchies & Networks
Flow ChartsSlide10
Iterative Design & Testing (cont.)
Interface Design (how user interacts
with product
or
system):
Provide good conceptual model (intuitive model)
Make things visible
Use natural mappings (intuitive)
Provide feedback (error messages, beeps, etc.
Prototypes (make ideas concrete, communication medium, usability testing)
Heuristic Evaluation (allows examination of every aspect of interface to assure meeting criteria)Slide11
Additional Evaluation Studies & Analyses
Cost/Benefit analysis
Trade-off analysis
Workload analysis (make something easier to use)
Simulations or modeling
Safety, human reliability, or hazard AnalysesSlide12
Usability Testing
Learnablility
Efficiency
Memorability
Error rate
SatisfactionSlide13
Support Materials
(Facilitators)
Repair Manuals
Assembly Instructions
Owner’s Manuals
Training ProgramsSlide14
Final Test & Evaluation
Two Most Common Research Designs Are:
Between-subjects design – different users perform tasks using the new product, the old product, or a different product.
Within-subjects design – same users perform tasks using the new product and comparison of productsSlide15
Measures
Proximal Measures
User satisfaction
Usability
Task performance levels (accuracy, task time, etc.)
Number of performance errors related to safety
Distal Measures
Manufacturing costs, efficiency, waste, etc.
Personnel costs
Number of accidents and injuries
Number of disability claims
Sick leave and other health indicesSlide16
Human Factors Change Programs
Company Audit:
Manufacturing equipment design
Environmental, workstation, & equipment safety hazards
Safety procedures & practices
Workstation design
Efficiency of plant layout
Efficiency of jobs/tasks
Adequacy of training
Organizational design and job structures
Reward or incentive policies
Information exchange and communication