Usability & Human Factors Unit 11 Input and Selection Methods

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


Keyboard/Mouse



Light-Pen



Voice Input/Speech Recognition



Speech Recognition:Advantages



Speech Recognition:Disadvantages



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



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



Ideal Features for Tablets



Touchscreen Input as Part of a Pharmacy Dispensing Unit



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



Tablets/Pen Input



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



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)



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/



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



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



Gestural Interfaces



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



Mechanics:Touch Screens, Gestural Controllers

(Saffer, 2009)



Gestural Interfaces:Use and Appraisal



Gestural Interfaces: Advantages



Gestural Interfaces:Characteristics of Good Design



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



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



Questions to Ask in Input Method Selection



More Questions



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



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/



Documents

Usability & Human Factors Unit 11 Input and Selection Methods