usability & human factors unit 11 input and selection methods
TRANSCRIPT
Usability & Human Factors
Unit 11Input and Selection Methods
Significance
Component 15/Unit 11 2Health IT Workforce Curriculum
Version 1.0/Fall 2010
Different input methods• Light pen• Pen & touchscreen• Mouse• Trackball• Voice recognition• Bar codes,• Special-purpose keyboards• Device touch pads with LCD
screens• Gesture-recognition systems • Haptic control
– Usually in conjunction with keyboard
» Sittig, 2010
• Input selection must be done with: – a view to context (physical,
cognitive)– Task– User population– Other variables
Component 15/Unit 11Health IT Workforce Curriculum
Version 1.0/Fall 20103
Keyboard/Mouse
Component 15/Unit 11Health IT Workforce Curriculum
Version 1.0/Fall 20104
Light-Pen
Component 15/Unit 11 5Health IT Workforce Curriculum
Version 1.0/Fall 2010
Voice Input/Speech Recognition
Component 15/Unit 11 6Health IT Workforce Curriculum
Version 1.0/Fall 2010
Speech Recognition:Advantages
Component 15/Unit 11Health IT Workforce Curriculum
Version 1.0/Fall 20107
Speech Recognition:Disadvantages
Component 15/Unit 11 8Health IT Workforce Curriculum
Version 1.0/Fall 2010
Zick & Olsen 2001
• Comparison of voice recognition and traditional transcription service for ED charts
• Voice recognition faster (avg 3.65min turnaround) v. transcription (39.6min)
• Transcription more accurate (99.7% v 98.5% for voice)
• Voice recognition improves in speed and accuracy; decisions made with current technologies at time of deployment
Component 15/Unit 11Health IT Workforce Curriculum
Version 1.0/Fall 20109
Tablets• Example: iPad• Form factor and light
weight; suitable for some applications
• 300 medical applications already developed
• Meets many requirements for healthcare tablet: – WiFi,– Dust/liquid resistant– Fingerprint authentication– Barcode scanning– Integrated camera
Component 15/Unit 11Health IT Workforce Curriculum
Version 1.0/Fall 201010
Ideal Features for Tablets
Component 15/Unit 11 11Health IT Workforce Curriculum
Version 1.0/Fall 2010
Touchscreen Input as Part of a Pharmacy Dispensing Unit
Component 15/Unit 11Health IT Workforce Curriculum
Version 1.0/Fall 201012
Pen Input• Handwriting recognition:
conversion of text in user-drawn image into digital form
• Difficult in practice• Gestural alphabets (palmtops,
cell phones) differ by brand• Digitizer tablets: learn user’s
handwriting; uses samples to train for accuracy
• Digital pen and special paper capture and recognize motion sequence
• Slower than keyboard input, virtual keyboards replacing it
Component 15/Unit 11 13Health IT Workforce Curriculum
Version 1.0/Fall 2010
Tablets/Pen Input
Component 15/Unit 11 14Health IT Workforce Curriculum
Version 1.0/Fall 2010
Pie Menus
• Faster than linear menus– Depend on direction rather than
distance• Circular menu slices large in
size, near pointer for fast interaction (Fitt’s law: ease of target acquisition is proportional to size and inversely proportional to distance)
• Ideally 3-12 items; 8 or fewer is best
• Muscle memory: experienced users need not look
• Can be nested for many options & pop-up linear menus
• Shows available options, unlike mouse gestures
Component 15/Unit 11Health IT Workforce Curriculum
Version 1.0/Fall 201015
Pie Menus (cont.)
• Useful for actions with logical grouping choices• Linear menus useful for dynamic large menus
without logical groups• Self-revealing gestural interface• Easy to ‘mark ahead’ because of memory without
menu even showing• Eases transition from novice to expert since every
use rehearses actions which go into muscle memory & item location unconsciously memorized
• Disadvantage: not often available as standard interface widgets (except in games)
Component 15/Unit 11Health IT Workforce Curriculum
Version 1.0/Fall 201016
Marking Menus
• Similar to pie menus but menu need not appear, multiple actions in chain can select desired item very fast, without need for menu to pop up visibly
• Combine pie menus with gestures
• See the excellent video at http://www.markingmenus.org/
Component 15/Unit 11 17Health IT Workforce Curriculum
Version 1.0/Fall 2010
Contextual Menus (Popup Menus)
• Appears on user interaction, in specific context
• Limited choices pertaining to current state
• Solution to need for rapid selection; also requires little memorization of location
• Problems:– Options available only in the context
may be confusing & not let user know of availability
• Screen edge interactions may be different
Component 15/Unit 11 18Health IT Workforce Curriculum
Version 1.0/Fall 2010
Yen (2005)Digital Pen/Paper
• Pen contains camera; records writing pattern on digital paper with 0.3mm dots
• Camera uses dots to track pen location, creating digital representation in memory
• Information transferred to computer; creates digital & paper copies
• Study: initial excitement gave way to use interchangeable with regular pens; preference for conventional pens due to bulk, distraction, not fitting in pockets
• Nurses saw potential, but physical execution needed improvement
Component 15/Unit 11 19Health IT Workforce Curriculum
Version 1.0/Fall 2010
Gestural Interfaces
Component 15/Unit 11 20Health IT Workforce Curriculum
Version 1.0/Fall 2010
Gestural Interfaces (cont.)• Multitouch 1 point of contact• Gestural commands less obvious, and less obvious
than current GUIs• May involve gloves, sensors, multiple cameras, LCD
arrays used as pinhole cameras• Output can be of multiple forms: music, video, device
control• Examples:
http://www.kickerstudio.com/blog/2009/04/a-collection-of-gestural-interfaces-spring-2009-edition/
• Interfaces can be almost invisible
Component 15/Unit 11 21Health IT Workforce Curriculum
Version 1.0/Fall 2010
Mechanics:Touch Screens, Gestural Controllers
(Saffer, 2009)
Component 15/Unit 11 22Health IT Workforce Curriculum
Version 1.0/Fall 2010
Gestural Interfaces:Use and Appraisal
Component 15/Unit 11Health IT Workforce Curriculum
Version 1.0/Fall 201023
Gestural Interfaces: Advantages
Component 15/Unit 11 24Health IT Workforce Curriculum
Version 1.0/Fall 2010
Gestural Interfaces:Characteristics of Good Design
Component 15/Unit 11 25Health IT Workforce Curriculum
Version 1.0/Fall 2010
Technology/Input Method Selection
• Should be based on consideration of the task, user, and environment
• Current technologies (such as voice input) may progress rapidly, so outdated studies and statistics should not be used
• Users may have a learning curve; comparison of two different methods should allow for training time (e.g. Kotani: study of pen-tablet v. mouse showed initial mouse superiority; then users became more efficient with pen-tablet
• See Mobile Devices for Nursing: a Human Factors Evaluation– http://www.medicine20congress.com/ocs/index.php/
med/med2009/paper/view/317
Component 15/Unit 11 26Health IT Workforce Curriculum
Version 1.0/Fall 2010
Appraisal of Input Methods• Some research on these comes from the field of
experimental psychology• Variables measured may include speed of
interaction, speed of data entry, accuracy, muscular and cognitive involvement, long-term, short-term and muscle memory, hand-eye coordination
• Results can vary from experimental laboratory to in-situ; try to test in the setting in which it will be used, with typical users
• Considerations such as size and weight can have significant consequences for whether item will be used, despite sophisticated software or other features
Component 15/Unit 11 27Health IT Workforce Curriculum
Version 1.0/Fall 2010
Questions to Ask in Input Method Selection
Component 15/Unit 11 28Health IT Workforce Curriculum
Version 1.0/Fall 2010
More Questions
Component 15/Unit 11 29Health IT Workforce Curriculum
Version 1.0/Fall 2010
Conclusions
• Input methods are an evolving field; standard methods (such as keyboard) will likely persist, but become device-independent
• New methods require research, but open up avenues of control useful in medicine.
• Gestural non-touch methods may be useful in situations where infection control, freedom of movement, lack of physical devices are key (e.g. ED, OR, pediatrics…)
• Matching the input method with senses and modalities involved in other parts of the task is more successful
Component 15/Unit 11 30Health IT Workforce Curriculum
Version 1.0/Fall 2010
Selected References• Buxton, William, Issues in Manual Input. User Centered System Design:
New Perspectives… (Paperback). by Donald A. Norman, Stephen W. Draper Chapter 15, p320-337
• Betriebsraum, B. Extremely Efficient Menu Selection: Marking Menus for the Flash Platform. December 11, 2009.
• Gestural Interfaces. http://www.kickerstudio.com/blog/2009/04/a-collection-of-gestural-interfaces-spring-2009-edition/ - A collection of gestural interfaces shown on video
• http://www.betriebsraum.de/blog/2009/12/11/extremely-efficient-menu-selection-marking-menus-for-the-flash-platform/
• Saffer, Dan. Designing Gestural Interfaces Touchscreens and Interactive Devices. . O;Reilly Media. Canada. 2009. See also http://www.designinggesturalinterfaces.com/
Component 15/Unit 11 31Health IT Workforce Curriculum
Version 1.0/Fall 2010