Context-Aware Mobile ComputingAMANDA DRAHEIM

Overview• Definition

• Examples

• History

• Issues

• Solutions

• Future

Definition• What is context?• “Context is any information that can be used to characterize the situation

of an entity. An entity is a person, place or object that is considered relevant to the interaction between a user and an application, including the user and applications themselves, and by extension, the environment the user and applications are embedded in. A system is context-aware if it uses context to provide relevant information and/or services to the user, where relevancy depends on the user’s task.” (Dey, 2001)

DefinitionWhat is context?◦ Information that is used to characterize the situation of an entity◦ Examples of Context:

◦ Temperature◦ User preferences◦ Lighting◦ Location◦ Nearby resources (such as printers)◦ History

DefinitionWhat is Context-Aware Mobile Computing?◦ Applications that can detect their user’s situations and adapt to

their behaviors accordingly.◦ A software that adapts according to it’s context!

DefinitionContext-Aware applications use context to:• Present services and information to a user• Examples: The time of day and restaurants near the user• Automatically execute a service for a user• Example: A phone automatically setting a weekly alarm for the user• Tag information to retrieve at a later time• Example: Phone keeps track of recent calls

Examples• Smartphone adjusts the screen to the orientation of the device• Orientation is determined by using both a gyroscope and an

accelerometer.

Figure 1

Examples• Phone display adjusts the brightness of the display based on the

surrounding area • Uses a light sensor

• Device uses GPS to display the user’s location• Can use to find nearby stores• Get directions• Status updates on Facebook!

Examples• The time is displayed on the phone.• Time zone change• Daylight savings time

Examples• Device disables touch screen when the user speaks on the phone• How?• A proximity sensor!• Uses infrared rays to send a signal out. The time it takes to be reflected back is

measured and from this, proximity can be detected.

Figure 2

Examples• Active Badge location system• One of the first context-aware applications – based on location• Call-forwarding system• Issues• Private call forwarding to a public room• Call is forwarded too important meeting

Examples• Schneider trucking trackers• Uses GPS to track loads• Sends a notification when a load nears it’s destination• Sends emergency notifications when conditions are met

Figure 3

History• First mention of context-aware computing was in 1991

• The term context-aware computing was coined in 1994 by Schilit and Theimer

• Smart phones become prevalent• Enabler for context-aware computing

History• Summary: The concept of context-aware computing as been

around for nearly two decades, but we are yet to reach the full potential of this technology.

Issues• Developers have little experience with devices that gather the

data. (i.e. gyroscopes)

• Data gathered from a sensor must be interpreted correctly in order for it to be useful.

• Context comes from various sources and in order for this data to be useful it must be combined correctly. (i.e. the gyroscope and accelerometer working together to determine orientation)

• The context changes constantly in real time can be an issue.

Issues• Increasing usability or decreasing control?• Automation reduces the amount of work that user’s have to do• User’s like the idea of a device that completes tasks on their behalf• However, when users use these devices they feel a loss of control if a

device has a high level of automation

Issues• Privacy Issues• Should law enforcement be able to access the history of a user?

• Context recognition is not always correct• Errors fusing data• Detection errors• Interpretation errors

• Application becomes too complex• Reduces accuracy of the application

Issues• User preferences may not match what the device does• Everyone is different!• What is your idea of nighttime?• What is your idea of warm? Loud?

• Information overload• Can overwhelm the user

Solutions• Keep an appropriate level of automation (avoid uncertainty)• The more automation we have, the less control we have over what

is happening.• What happens if we give all control to machines?• Would you trust your phone to give you a dose of medicine?• Keep a balance between uncertainty and automation.

Solutions• Avoid unnecessary interruptions• Phone flashes a notification every 30 seconds• Eventually the user will ignore it!

• Avoid information overload• Too much information can overwhelm the user, and bog down the

device• Example: Walking down a busy street a user’s device is bombarded

with suggestions of places to shop

Solutions• Be sure the user feels in control of the application• Too many automated actions = loss of control• A balance between automation and user control needs to be found• Smart Actions - A good balance.

Solutions• Keep an appropriate level of system status visibility• Allow the user to see what action the device is taking• Be sure the user understands why the device is performing the

action

• Account for the impact of Social Context• A loud alert is not ideal for all situations

• Allow for the personalization of individual needs• Allow user to change locations names (set a location name to

“home” for example)• Smart Actions

Solutions• Secure the user’s privacy• Selling information to advertisers…is this right?• Giving information to the police, when does this cross the line?• Sharing context information with others—Facebook location

Future• Healthcare devices• Blood sugar• Carbon monoxide detectors• Breathalyzer• Fall detection

Future• In law enforcement• Ability to solve crimes using contextual information from devices

• In vehicles • Cars that are able to drive themselves• Collision avoidance• Warning if departing lane• Automatically adjusts seats and headrests to avoid whiplash• Warns if a car is in blind spot when changing lanes

Future• Retail• An application could make smart recommendations based on where

you have eaten in the past• Types of food• Budget• Atmosphere• Retailers can use smartphones to be able to tell the types of products

you buy and send advertisements/coupons based on those products.• Use RFID chips in the products• Able to tell what consumer buys and send relevant coupons.

Future• Gaming• Use of the gyroscope will revolutionize mobile gaming• Wii is an example of the use of a gyroscope• Can phones incorporate the same technology?• Example: Google Sky Map ( accelerometer only)• Example: Gun Range App for iPhone( gyroscope and accelerometer )

Questions?

Resources• Dey, Anind K. and Jonna Häkkilä. "Context-Awareness and Mobile Devices."Handbook of

Research on User Interface Design and Evaluation for Mobile Technology. IGI Global, 2008. 205-217. Web. 26 Feb. 2013. doi:10.4018/978-1-59904-871-0.ch013

• Guanling Chen and David Kotz, "A Survey of Context-Aware Mobile Computing Research." Dartmouth Computer Science Technical Report TR2000-381, November 2000.

• B. Schilit, N. Adams, and R. Want. 1994. Context-Aware Computing Applications. In Proceedings of the 1994 First Workshop on Mobile Computing Systems and Applications (WMCSA '94). IEEE Computer Society, Washington, DC, USA, 85-90. DOI=10.1109/WMCSA.1994.16 http://dx.doi.org/10.1109/WMCSA.1994.16

• Tamas Vajk, Paul Coulton, Will Bamford, and Reuben Edwards, “Using a Mobile Phone as a “Wii-like” Controller for Playing Games on a Large Public Display,” International Journal of Computer Games Technology, vol. 2008, Article ID 539078, 6 pages, 2008. doi:10.1155/2008/539078

Images and Media• Figures

1 - http://blog.nasm.si.edu/2010/09/21/ballistic-missile-guidance-on-your-cell-phone/

2 - http://thecodeartist.blogspot.com/2011/01/proximity-sensor-on-android-gingerbread.html

3 - http://logisticsweek.com/wp-content/uploads/2010/04/schneider.jpg

• Videos

Car video: http://www.youtube.com/watch?v=B9lubGxD6BM

Gyroscope game: http://www.youtube.com/watch?v=veN-WHhtcjs