HCI Lecture 14 Special Issues: Ubiquitous computing Barbara Webb Key points: Making the computer part of the environment Mobile devices Implicit input Ambient output Continuous interaction Issues for design and evaluation 1
Introduction Human-computer interaction addresses the relationship between humans and computers, doing tasks in environments Task Human Computer Environment The focus should be on supporting human activities Ideally, the computer would just be part of the background environment in which we do the task This concept has been called invisible, pervasive or ubiquitous computing (Weiser, 1991) 2
Introduction Computation beyond the workstation or desktop computer (fixed location, screen, keyboard & pointing device). Includes: Handheld, portable and wearable devices Mobile phones, PDAs, digital cameras, sat-navs etc. 3
Introduction Computation beyond the workstation or desktop computer (fixed location, screen, keyboard & pointing device). Includes: Handheld, portable and wearable devices Mobile phones, PDAs, digital cameras, active badges etc. Very different scales or styles of output Very small and very large displays, distributed, 3-dimensional Richer sounds, device actuation, ambient cues Augmented vs. virtual reality 4
Introduction Computation beyond the workstation or desktop computer (fixed location, screen, keyboard & pointing device). Includes: Handheld, portable and wearable devices Mobile phones, PDAs, digital cameras, sat-navs etc. Very different scales or styles of output Very small and very large displays, distributed, 3-dimensional Richer sounds, device actuation, ambient cues Virtual or augmented reality Novel forms of input Pen-based, touch based, proximity sensing Voice operated Tilt or motion sensing Implicit input location, time, context Embedded computers in other technologies Cars, washing machines, etc. Instrumented rooms, buildings, environments 6
Introduction Often these factors interact: Mobile device Reduced power and functionality Smaller interface Specialised for certain functions Alternative I/O methods Task specific interfaces Improved usability! 7
Guidelines for Small Devices Should distinguish mobile (usable while moving) from portable (movable but need to be stationary to use successfully) Use(fulness) immediately apparent Structure interface to task Short cuts and flexibility Minimise memory load Use consistent screen templates Provide a Back function on every screen Selection is better than writing 8
Small devices and the web Increasingly common for mobile devices to access the internet Important constraints: Smaller screens show less, so memory load increases Have awkward and error prone input methods Very wide variety of device specifications (screen size, resolution, layout, interaction options) compared to standard desktop/laptop More connectivity and bandwidth issues People are unlikely to try to do all the tasks offered by the full site using their mobile device Ideally should always make alternative mobile site available, and make it easy to switch between this and the full site General principle: being able to do anything tends to make everything take longer to do. 10
Norman s The Invisible Computer Personal computer is massive, impersonal, abrupt and rude, used mostly to do social things and not for computing A device that does everything will be convenient but will probably perform worse than specialised devices: Swiss army knife vs. kitchen knife, corkscrew, screwdriver, scissors Also get incremental addition of features, amount of information stored (disk space), amount available (WWW), so can no longer make everything visible or discoverable Norman suggests technology should move towards information appliances, i.e. many items serving specific needs: Home financial centre in right location with right connections Displays providing weather, news, sports (compare to clock) Foreview mirror in cars for traffic, parking spots 11
Norman s The Invisible Computer Devices that are easy to use, not only because they will be inherently simpler, but because they fit the task so well that to learn the task is to learn the appliance. Simplicity and visibility of function paramount Will require infrastructure to allow seamless information transfer between devices 12
The iphone Opposite direction: towards multipurpose device Sensors: proximity, ambient light, accelerometer (orientation) and touch screen several advanced touch features Loss of physical buttons removes tactile landscape See http://www.computerworld.com/ for usability test 13
Natural interaction Much concern in HCI about finding more natural forms of input `Context aware computing suggests computers should be able to recognise implicit inputs: E.g. walking into a space should be sufficient to announce your presence and identity More generally, tracking the user s location to supply them with relevant information (satnav) Alternative forms of identification also have many obvious applications (with varying requirements for reliability) Time is another implicit cue: could exploit to detect interest, deviation from routine, even identity General idea is that input is a side-effect of doing the activity Automated capture as a background technology 14
Invisible interaction Potential to eliminate conscious interaction E.g. remove ticket sales by tracking where people went and charging their accounts Verichip implant Identify patients in emergency situtation Other uses? Replaces interaction programming problems with ethical problems Those without resources to be connected to system are disenfranchised Removes option of anonymous interaction 15
Natural interaction Tangible input devices manipulate ordinary physical object 16
Continuous interaction Obtaining natural interaction may involve collapsing the usual input/ output distinction `Continuous interaction emphasises the closed loop rather than stages of action Goals Sequence of actions The world Evaluation Ongoing activity The world On more extended time scales, includes thinking of HCI in terms of extended, ongoing activities rather than tasks that have a clear beginning and end Should support interruptions, concurrency etc. 17
Design processes for continuous interaction what is wanted Importance of ethnography in assessing user requirements (don t trust post-hoc rationalisation) analysis Augment task analysis with: Instantaneous information requirements: will it be part of task, users memory, computers memory, or in environment? Trigger analysis: does next step occur immediately, after fixed or variable delay, or in response to external event? prototype design implement and deploy 18
Evaluation of ubiquitous computing Some problems for evaluation Hard to measure relevant variables Inappropriate to use methodologies that interfere with the normal process (e.g. co-operative evaluation, lab experiment) Need long term analysis May be fuzzy usability criteria Standards and guidelines are developing for mobile devices, but still lagging for more immersive technologies 19
References Weiser, M. (1991) The computer for the 21 st century. Scientific American, 265/3: 94-104 Norman, D. (1998) The Invisible Computer, MIT Press Williamson, J. Murray-Smith, R. & Hughes, S. (2007) Shoogle: Multimodal Excitatory Interfaces on Mobile Devices, CHI 2007 See also: Dix et. al. sections 18.3, 18.4 chapter 20 20