Chapter 3 Reference Slide 2 of Lecture 1

 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 otherwise

 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 point

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 involved

 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)

1. ID end users & analyze population characteristics 2. ID major system functions (function & task analyses) 3. Determine environment for use 4. ID user preferences/requirements - do system functions match? 5. Are there any existing constraints in system design? 6. What are the human factors criteria for design solutions?

 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.

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 tasks

 Structured Vs Unstructured Interviews  Observation  Think Aloud Verbal Protocol  Task Performance Questioning  Representing Data with Lists, Outlines, Matrices, etc.  Hierarchies & Networks  Flow Charts

 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)

 Cost/Benefit analysis  Trade-off analysis  Workload analysis (make something easier to use)  Simulations or modeling  Safety, human reliability, or hazard Analyses

 Learnablility  Efficiency  Memorability  Error rate  Satisfaction

 Repair Manuals  Assembly Instructions  Owner’s Manuals  Training Programs

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 products

 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 indices

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