Comp 15 Usability Human Factors Unit 8 c
Comp 15 - Usability & Human Factors Unit 8 c - Approaches to Design This material was developed by Columbia University, funded by the Department of Health and Human Services, Office of the National Coordinator for Health Information Technology under Award Number 1 U 24 OC 000003.
Design Principles to Support Usability (Dix et al, 2004) Learnability • Ease with which new users can achieve a) basic proficiency and then b) mastery Flexibility • Flexible ways in which the user and system exchange information Robustness • Level of support provided to user in determining successful achievement and assessment of goals Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 2
Learnability Factors Predictability • Support for the user to determine the effect of future action based on past Synthesizability • User can understand effect of past operations on the current state of system Familiarity • Extent to which a user’s knowledge and experience can be applied when interacting with a new system Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 3
Learnability Factors Cont. Generalizability • Support for the user to extend knowledge within and across applications Consistency • Likeness in input-out behavior arising from similar situations or similar task objectives Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 4
Usability Principles and Design Heuristics (Nielsen, 1993) Visibility of system status Error handling Match between system and the real world Recognition rather than recall User control and freedom Flexibility and efficiency of use Consistency and standards Aesthetic and minimalist design Error prevention Help and documentation Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 5
1. Visibility Keep users informed Make state transitions explicit Animate dynamic processes Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 6
Be Obvious Where am I? What’s happening? What can I do? What do I need to know? Most users are not interested in “exploration” Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 7
Animate Slow Processes Progress Bar Added Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 8
2. Match System to World Speak the users' language • Avoid Jargon Follow real-world conventions Present information in a natural and logical order. Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 9
3. User Control and Freedom Clearly marked "emergency exit" Support undo, redo and “back” User configurable preference and interfaces Avoid fixed sequences Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 10
4. Consistency and Standards Consistent placement Consistent action models Beware modal behaviors Follow platform conventions Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 11
The Law of Least Astonishment The system should never “surprise” the users. It should always behave in the “expected” manner Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 12
5. Error Prevention Make “bad things” hard to do Identify errors early • Data checks before “submit” Confirm unrecoverable actions Avoid “dialog escape” Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 13
6. Error Handling Help users recognize, diagnose, and recover from errors Error messages should be expressed in plain language • No codes Precisely indicate the problem • The very worst error messages are those that don't exist Suggest a solution Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 14
Some Favorite Error Messages Abort? Retry? Fail? Ignore? -3162 Incorrect Magic Number 207. 171. 0. 250 does not like recipient. Permanent Compiler Error Panic Error: An unexpected error has occurred Error: The operation completed successfully Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 15
7. Recognition, not Recall Minimize users’ memory load Make objects, actions, and options visible. • Minimize hidden functions Instructions visible or easily retrievable. Make sequential steps explicit • The user should not have to remember information from one screen to another. Minimize command languages Proper Default Doses & Routes Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 16
Icon If You Can Use icons to reinforce content Pictures recalled better than words Test your icons Avoid subtle distinctions Avoid “cute” metaphors Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 17
8. Flexibility and Efficiency Allow users to tailor frequent actions. Keyboard Shortcuts Macros / Scripting Programmable Interfaces Order Sets Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 18
9. Aesthetic and Minimalist Design Screen content should relate to user’s goals Many users will not be able to separate relevant from irrelevant Design and Decoration should enhance visibility The removal test • Remove item • Test application • If the application still works, leave it out Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 19
Color With Care Design in black and white Four or fewer colors Avoid saturated colors Do not encode only in color Use color consistently Avoid color opposites Beware unintended color meaning Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 20
Funday Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 21
10. Help and Documentation No one reads the manual • … until something breaks Plan instructions for problem solving Many users accustomed to paper, not computer Step-wise, pictorial instructions Invaluable for remote support Test your documentation Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 22
Reducing System Barriers for Older Adults IDEATel Informatics for Diabetes Education And Telemedicine Large-scale home-based telemedicine project for medically-underserved diabetic patients • Older adults with limited computer literacy Usability testing revealed a range of user problems that impeded productive use Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 23
Changes to Design Simplify without reducing functionality! Go Big: large text and buttons Reduce memory load/minimize task complexity Improve contrast Enhance navigation Reduce burden on psychomotor skill • Mouse-based system to touch screen Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 24
Generations Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 25
Gen 1 a Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 26
Gen 1 b Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 27
Gen 2 Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 28
Pedometer Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 29
References Dix A. , Finlay J. E. , Abowd G. D. , Beale R. (2004). Human-Computer Interaction. 3 rd ed. Essex, England: Prentice-Hall; . Kaufman D. R. , Patel V. L. , Hilliman C. , Morin P. C, . Pevzner J. , Weinstock R. S. , et al. (2003). Usability in the real world: assessing medical information technologies in patients' homes. Journal of Biomedical Informatics. Feb-Apr; 36(1 -2): 45 -60. Mayhew, D. J. (1999). The usability engineering lifecycle. San Francisco, CA. : Morgan Kaufmann Publishers, Inc. Nielsen, J. (1994). Heuristic evaluation. In J. Nielsen & R. L. Mack (Eds. ), Usability Inspection methods (pp. 25 -62). New York: Wiley. Norman DA. Cognitive engineering. In: Norman DA, Draper SW, editors. User centered system design: New perspectives on human-computer interaction. Hillsdale, NJ: Lawrence Erlbaum Associates; 1986. p. 31 -61. Polson, P. G. , Lewis, C. , Rieman, J. , & Wharton, C. (1992). Cognitive walkthroughs: A method for theory-based evaluation of user interfaces. International Journal of Man-Machine Studies, 36, 741 -773. Preece, J. Rogers, Y. & Sharp, H. (2007) Interaction Design: Beyond Human-Computer Interaction. 2 nd Edition. New York, NY: John Wiley & Sons Ruland CM, Starren J, Vatne TM. Participatory design with children in the development of a support system for patient-centered care in pediatric oncology. J Biomed Inform. 2007 Nov 13; Shea, S. Starren, J. Weinstock, R. S, Knudson, P. E. , Teresi J. and Holmes, D. et al. , Columbia University’s Informatics for Diabetes Education and Telemedicine (IDEATel) Project: rationale and design, J Am Med Inform Assoc 9 (1) (2002), pp. 49– 62. Starren J, Hripcsak G, Sengupta S, et al. Columbia University's Informatics for Diabetes Education and Telemedicine (IDEATel) project: technical implementation. J Am Med Inform Assoc. 2002; 9: 25– 36. Starren, J. Weinstock, R. S, Palmas, W. , Izquierdo, R. , Morin, P. and Kaufman, D. R. Diabetes. In: R. Wootton, S. L. Dimmick and J. C. Kvedar, Editors, Home telehealth, Connecting care within the community (2006), pp. 171– 183. Component 15/Unit 8 c Health IT Workforce Curriculum Version 2. 0/Spring 2011 30
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