Collaborative Applications

1
Collaborative Applications
Prasun Dewan
Department of Computer Science University of
North Carolina CB 3175 Sitterson Hall Chapel
Hill, NC 27599-3175 dewan_at_cs.unc.edu http/www.c
s.unc.edu/dewan
2
Definition
Collaborative Application
I/O
I/O
Coupling
User 2
User 1
Potentially Real-Time
3
Traditional Collaborative Applications
File
Mail
Talk
save
load
send
receive
hi hello
hi hello
User 1
User 2
User 1
User 2
User 2
User 1
4
Novel Collaborative Applications
File
Mail
Talk
File Mail
Talk Mail
Talk File
File Mail Talk
5
Talk

• Talk
• Mail
• File
• Talk Mail
• Talk File
• Mail File
• Talk Mail File

6
Talk Screen Division

• Screen gets divided among two users.
• Each portion shows history of users input.
• Each users input seen incrementally.
• N-Users?

7
Semi-Synchronous N-User Talk

• A single history shared by all users
• Users input not seen incrementally.
• Concurrent unseen typing can lead to history
  misinterpretation
• User does not know if newly shown text was
  entered concurrently

8
Horizontal Time Line
Horizontal time line in Flow Chat (Vronay, Smith
et al. 99),

• Long conversations will not fit.
• Incremental input of users in other threads of
  conversations distracting

• Users see concurrent input.
• Time line of committed text for third party
• Textless box created for uncommitted text

9
Vertical Time Line

• Comic-book metaphor
• Incremental input not shown empty balloon
  created
• Does not work for large users

Vertical time line in Freeway (Vronay 2002)
10
Threaded Chat

• Scales to large users supports long
  conversations
• New message response to clicked message.
• Incremental input not shown, but empty box
  created
• Chronological order not shown
• New items gradually fade to grey.
• Fewer messages, balanced participation, but users
  less comfortable and same task performance.
• Overhead of responding to message?
• Associate default thread with message
• Designed for N-users, and synchronous/asynchronous
  
• Not as useful for 2 person or pure synchronous
  communication

Threaded Chat (Smith, Cadiz et al. 2000)
11
Babble Persistent Sessions and Involvement Degree

• User List
• Involvement Degree
• Topic List
• Current messages

dewan
CSCW Demo
wu
Faculty Retreat
sherman
Comp 14
omojokun
From PD Is the grading sheet ready

• Persistent sessions
• Social topics synchronous
• Work topics asynchronous

From Omojokun About to post it.
Bradner et al 99
12
MUDs Textual Virtual Reality
(Wizard)
John has entered the room (hear footsteps)
Say Hi everyone
Emote smiles
Whisper Boring to Joe
Look John
You whisper, Boring to Joe
Johns textual description
_at_who
Move John to public place
Name Connect Idle Time
Time
Change Johns description
Disallow John whisper
Disallow John from this room
Make John a wizard
13
Line of Site Graphical VR

• MUD place represented as 3-D space
• Users represented as avatars in 3-D space.
• Line of site communication
• Move avatars close to users of interest.
• Can express emotions

Avatars in V-Chat (Smith, Farnham et al. 2000)
14
DIVE Aura-based Graphical VR

• Avatar interaction
• With another user enables communication
• With app enables sharing.
• Transitive
• Multiple auras
• Podium - perception and communication. Determine
  whether can speak into/hear the speaker.
• Table perception and distribution. Determine
  if distributed document is shared or private.

Aura
User 2
User 3
Application
User 1
User 4
Fahlen, Stahl et al 93
15
MASSIVE Aura and Nimbus
Aura
Nimbus
User 1
User 2

• Speakers aura must intersect listeners nimbus
• User 2 can hear User 1

Greenhalgh Benford 95
16
MASSIVE Aura and Nimbus
Nimbus
Aura
User 1
User 2

• Speakers aura must intersect listeners nimbus
• User 1cannot hear user 2

Greenhalgh Benford 95
17
Elvin CofeeBiff Textual Remote VR
of people in coffee room
Scrolling user list.
Can get notified when gt threshold (party!)
18
Video Walls Video-based Remote VR
Camera Microphone
Camera Microphone
Screen Speaker
Screen Speaker
Room 1
Room 2
19
Two Remote Rooms

• Goal spontaneous collaboration
• 3 Kitchens connected
• See CNN to attract attention
• Moderately useful
• N rooms?

Display of two remote kitchens, local image, and
video to attract attention (Jancke, Venolia et
al. 2001)
20
Media Space
Map
Room 2
Room 4

• Selecting a room starts video conference with
  user
• Can be abrupt

21
Office Walker

• Each office has virtual neighbors
• Clicking on office places caller in virtual
  hallway
• Neighbors can see small image.
• User can approach to create bigger image.
• Office worker, neighbors, visitors can initiate
  talk.

Interaction Model (Obata, Sazaki 98)
22
Two Remote Rooms

• Media space/Office Walker intended for 1-1
• Connected Kitchens can be used for 1-N
• Speaker focus?

Display of two remote kitchens, local image, and
video to attract attention (Jancke, Venolia et
al. 2001)
23
Overview Speaker

• Omni-directional set of cameras to create
  overview image.
• Shot of current speaker sent separately.
• Speaker can be selected manually by buttons.
• Auto detection
• Speakers voice received by his microphone first.
• Audio triangulation can be used when each speaker
  does not have microphone.
• Custom zooming?
• on non speaker or speaker?

Overview, speaker and persons selection buttons
(Rui, Gupta et al. 2001)
24
3-D Telepresence

• Multiple cameras used to create 3-D Model of Room
• Remote site can navigate in this model
• With or without tracking
• Can focus on speaking person
• Or patient!

UNC Office of the Future
25
Gesture Cam Remote Surrogate

• Can determine which objects to look at
• As in office of the future
• Can point to specific objects
• As in Clearboard

Figure originally appears in 30
26
Gesture Cam Architecture
Figure Originally appears in 30
27
Colab. PsyBench
28
PsyBench
29
Psy Bench Architecture
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In Touch
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In Touch Architecture
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Merging Graphical VR and TelePresence?
33
Mixed reality Internet Foyer

• Physical Foyer
• Public visiting place
• Virtual foyer
• 3-D image visualization of web pages with avatars
• Clicking on page opens the page shows 2-d images
  of people browsing it.
• Mixed reality
• Physical foyer has video wall to 3-D
  visualization and avatars
• Virtual foyer has video of physical foyer

Benford 95
34
TELEP Presentation to large users
Lecture Site
Remote Site

• Questions seldom asked
• Local audience not seen remotely

  Display at lecture (left) and remote site
(right) (Jancke, Grudin et al. 2000)
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Video Production Lecture

• Same screen for lecture and audience view
• Switch to speaking audience member as soon as
  tracked
• If no one tracked, show overview
• If lecturer speaking, occasionally show random
  audience member
• A shot should be shown for a max and min time.
• Always show person from the same side.
• Two consecutive shots should be very different

 Figure 4 Cameras and their placement (Liu, Rui
et al. 2001)
36
Video vs. App. Sharing

• Screen shot can be shared through video broadcast
  or app sharing
• App sharing cheaper, with better fidelity.
• Allows collaborative input.
• E.g. multiple presenters
• Integrating with video for non-computer objects?

37
TeamWorkstation Integrated Desktop Computer
Awareness

• Each user has personal and shared computer
• Shared computer can provide various overlays

(Ishii 90)
38
TELE-SCREEN
Editing paper xxxx yyyyy
39
TELE-DESK
Editing paper xxxx yyyyy
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SCREEN-OVERLAY
Editing paper xxxx yyyyy
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DESK-OVERLAY
Editing paper xxxx yyyyy
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SCREEN DESK OVERLAY
Editing paper xxxx yyyyy
43
COMPUTER SHARING

• Computer shared by capturing and distributing
  video to the monitor
• Keystrokes also captured and distributed by
  hardware.
• Everything overlaid is video
• No software needed

Editing paper xxxx yyyyy
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SUMMARY OF MODES
(Ishii 90)
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Awareness of Collaborator

• Must look away from work area to see
  collaborators image.
• Do not know what object the collaborator is
  gazing at.
• Overlay Video?

46
Clearboard Collaborator Awareness
Figure available from http//ishii.www.media.mit.e
du/people/ishii/CB.html.
47
Clearboard Drafter Mirror

• Coupling two non electronic whiteboards.
• Half-slivered mirror
• Fluorescent marker
• See two hand images
• One captured directly
• One reflected
• Polarized film and filter on each camera prevents
  feedback between screen pairs

Figure first appeared in 26
48
Clearboard Architecture

• Mirror image transmitted when LCD screen in
  transparent mode.
• Video projected when in scattering mode.
• Digitizer pen used to track user input.

Figure first appeared in 26
49
Two Gaze Awareness Problem

• Object of interest Do we know what object on the
  screen the collaborator is looking at.
• Clearboard and Facetop address this.
• Person of interest Do we know which one of many
  collaborators a person is addressing
• Hydra, MAJIC address this

50
Hydra Gaze Awareness

• Images too small to give good user experience

Figure originally appears in 5.
51
MAJIC Real-Life with Seamless User Boundaries

• Similar idea in office of the future
• From talking head to large (projected images)
• Gives more of a feeling of being there
• Solving different problems

Figure originally appears in 36
52
Talk Being there vs. beyond

• Beyond being there
• Teleporting to room
• Whispering not noticed by those not included
• Aura and nimbus customizable
• Anonymity, Presence Control
• Multitasking
• Involvement degree and conversation status
• Talk history
• Threads structuring conversations
• Computer controls
• Asynchronous collaboration

• Being there
• Real-time communication
• Peripheral awareness
• Footsteps, hallway
• Moods
• Aura
• Nimbus
• Video
• Remote view control
• Remote pointing
• Haptics
• Human access control
• Podium, sharing documents in a table

53
Anonymity

• In theory participants can be more bold
• In an experiment perceived status did no harm
  (Davis, Zaner 2002)

54
Presence Control

• Presence
• Location
• In-use computers
• Activities
• Computer and other

• TELEP Presence Options
• Video, photo, text
• Users liked not sending video
• Collaborator is often required to poll for
  presence in meeting (Mark, Grudin 99)
• Moral presence status?

55
Multitasking

• Reduced commitment to meeting and less engaged
  (Mark, Grudin et al. 99).
• But may be willing to attend more meetings!
• TELEP Teachers more willing to cover elementary
  stuff knowing advanced students can tune out (S.
  A. White, A. Gupta et al. 2000)

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Meeting video browsing
(Li, Gupta et al. 2000)
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Video Processing

• Pauses in speech and associated video removed.
• Time compress without changing pitch
• Table of contents generated manually.
• Shot boundaries generated by detecting
  transitions
• Bookmark and annotate
• Jump to next/previous
• Bookmark
• Shot Boundary
• Slide transition
• Time boundary

• Application of pause/removal, rime compression
• Sports video Lectures
• Upto 147 playback speed
• Not TV dramas!
• Shot boundaries
• Sports programs (high variation in content)
• Not lectures

(Li, Gupta et al. 2000)
58
Automatic Slide Summaries

• Allocate time at beginning proportional to slide
  time
• Slide time proportional to slide importance
• Important things explained at beginning
• Include higher-pitch information
• Pitch increases when excited

• Both techniques found equally good and
  acceptable.
• Not as good as author-generated summaries

(He, Sanocki et al. 1999)
59
Other Slide-based Summarization Techniques

• High information density
• All three methods as good as author-generated A/V
  summaries
• Low information density
• Highlighted text as good as author-generated A/V
  summaries

• Slides only
• Slides text transcript of audio
• Slides text transcript points in text summary
  highlighted

(He, Sanocki et al. 2000)
60
Chat History Issues

• Snap-back scrolling
• In Flow Chat
• Scrolling takes us back in time
• Releasing scrollbar returns to present
• Can be used for any history-based tool

• People hardly use history.
• Hard to scroll back and forth.
• Designed for passive text
• Chat is active text being changed under you.

61
Elvin Ticker-Tape History with TimeOut
Fitzptarick et al 99
colabvibhor merging of vector works
colabpd Great! Give demo sometime.
62
Scripted Collaboration

• Computer acts as moderator
• Determines issues discussed and allocated time
• After using it rules enforced manually.

(Farnham, Chesley et al. 2000)
63
rIBIS Real-time Structured Issue Resolution
I Which processor should be used
Resolved issue
Unresolved position
?P Processor A
Argument Supporting
AS Fast
P Processor B
Current position
AS Cheap, already in use
-P Processor C
Rejected position
AS Cheap fast
Argument objecting
AO Will not be available in time
Rein Ellis 91
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Implicit structure for status

• Messages automatically classified into comments,
  questions, responses.
• Based on presence of ?
• Statistics shown about them.

Threaded Chat (Smith, Cadiz et al. 2000)
65
CLARE Structured Discussion Process Model

• Structured discussion a la IBIS (RESRA -
  Representation Schema of Research Artifacts)
• paper is source
• addressing some problem
• about which a claim can be made
• supported by evidence
• generated by research methods
• defining concepts
• Process model (SECAI )
• Summarization (Privately create RESRA)
• Evaluation (Private critique it)
• Comparison (Publicly compare them)
• Argumentation (Publicly critique them)
• Integrate (The various RESRAs)

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RESRA
Figure originally appears in 39
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SECAI
Figure originally appears in 39
68
Mail

• Talk
• Mail
• File
• Talk Mail
• Talk File
• Mail File
• Talk Mail File

69
Threaded Email
(Venolia, Dabbish et al.)

• Messages shown chronologically
• Special lines created to show parent-child
  relationship
• Messages grouped by day today, yesterday

• Groups messages, gives context
• Useful after vacation
• Thread-based commands
• Delete thread
• Forward messages and subscriptions

70
Prioritizing mail messages
(Horvitz, Koch et al. 2002)
71
Prioritizing mail messages

• Automatically prioritize mail messages based on
• organizational relationship to sender
• proximity of send time to key times for sender
• message length and body
• how long message waiting

(Horvitz, Koch et al. 2002)
72
Messages to mobile device

• Goal cause minimal disruption.
• If user not active gt T message priority gt P
• Send to mobile device
• P function of
• Whether user in meeting.
• Determined from calendar
• Other factors.
• Replace
• Not active gt T with
• Likely to be away gt T

(Horvitz, Koch et al. 2002)
73
Messages to mobile device
(Horvitz, Koch et al. 2002)
74
Presence Forecast

• Determine when mobile user is likely to return to
  office and remain there for some time
• e.g. probability of user returning within 15
  minutes and remaining for 30 minutes
• Based on
• activity with desktop
• patterns of past behavior
• aggregate
• lunch, morning, afternoon, evening, night
  behavior
• how long user has been away

75
Presence Forecast
p(Client activity within 15 min. time away,
time of day)
Lunch
Night
Probability of return within 15min
All
Afternoon
Morning
Evening
Time away
(Horvitz, Koch et al. 2002)
76
SMART OOF
(Horvitz, Koch et al. 2002)
77
SMART OOF
(Horvitz, Koch et al. 2002)
78
SMART OOF

• SMOOF Smart out of office message
• If message priority is gt threshold send presence
  estimate

(Horvitz, Koch et al. 2002)
79
Time Wave

• Office Presence forecast
• Updated continuously based on how long user has
  been away

(Horvitz, Koch et al. 2002)
80
Time Wave
(Horvitz, Koch et al. 2002)
81
Time Wave

• Email review forecast
• Updated continuously based on prev. email history

(Horvitz, Koch et al. 2002)
82
(No Transcript)
83
Time Wave

• Cost of interruption forecast, associated with
• time of day, free period

(Horvitz, Koch et al. 2002)
84
(No Transcript)
85
Coordinate Multi Device System

• Track user activity on multiple devices
• Forecast which devices accessible
• Useful because
• devices may imply location
• caller knows to send email or call mobile phone
• capabilities required by caller may be device
  specific
• certain devices allow video conferencing

86
Other forecasts

• Based on user activity, data, and input can
  determine
• whether a person will attend a meeting
• calendar
• meeting duration
• running vs. one-time meeting
• invitation specific or to group

87
Information Lens Typed Messages
Malone 87
88
Coordinator Structured Conversation
Customer
Producer
Automation of form fields alerts,
reminders status information
Flores et al 88
89
Action Workflow
Status By Candidate Workflow Step
Manage Review
Manager
Director
Medina Mora 92
90
ATOMICMAIL Computational Mail
Data
Program
display/animate graphics gather data and mail
Lisp-based PL Single Directory
Accessed File Creation Limited Mail
Messages Limited
Mail Receiver
Borenstein 92
91
File

• Talk
• Mail
• File
• Mail File
• Talk Mail
• Talk File
• Talk Mail File

92
State of the art file system

• Access control
• Locking
• Versioning
• Disconnected access
• Hoarding
• caching data needed in disconnected access
• Directory merging on connection
• Adds composed
• Deletes cancel.
• File granularity
• Programmer-defined merge procedure
• Local area network

93
Application-level Support

• Disconnected access and merging of
• Calendars
• Address book
• Word
• Powerpoint
• Not Excel.

94
Lotus Notes P2P Database Replication
Replica
Replica
source determines
read access
delete replication old data replication
replication schedule
destination determines
write access type replication record
replication ACL rep. rep. param. rep.
immediate rep.
Table record-based merging
95
Groove Workspace

• Groove workspace
• Wide-area replicated storage
• Like Lotus Notes but with a file-system like UI
• Replicas merged on connection time
• As in Lotus Notes
• Intuitive access control based on making and
  accepting invitations.

96
Chronicle Fine-grained Spreadsheet Versions

• Named Range
• Unit of naming, storage, versioning
• Rectangular cell block
• Range name
• User-defined annotation
• User id
• Date
• Compose named ranges
• Sallys expense data Joes sales data
• Try different alternatives of named range
• Sallys expense forecast
• Joes expense forecast
• Ranges can be browsed, mailed
• Concurrent editing of named range automatically
  creates versions

97
Mail File

• Talk
• Mail
• File
• Mail File
• Talk Mail
• Talk File
• Talk Mail File

98
Mail File

• Version system ala multiple mail copies.
• Editing sent file
• before mail receipt
• after mail receipt
• allows users to have own file name spaces, easy
  access control
• Sending access permissions via mai
• a la groove invitations
• Sending same file to a group of users
• creates a single copy of file on accessible
  shared (sharepoint) site

99
POLITeam Shared Workflow Documents

• Workflow
• Structured mailing of documents.
• Breaking workflow
• Received document can be shared with others

100
News

• Like file, logically centralized information
  shared among multiple users.
• As in mail, users view/modify information by
  receiving/sending/responding to messages.

101
News Shared Mailboxes
Message 1
User 1
User 1
Message 2
User 2
User 2
Send
Receive
User N
User N
Message M
102
Scaleable Modifiable Information

• Wide area shared information.
• Scales to the whole world.
• Cannot build such a file system.
• How can we build News?
• Loose consistency as in Notes and Groove!

103
News Scaleable Architecture
read news
post news
eventual delivery of immutable messages in
possibly different order
104
Message/News Filtering

• Agent-based
• Newsgroup
• Discussion Thread
• Urgent Message
• Sender Cost
• Contents of Messages (Data Mining)

• Rating-based
• Moderator
• Known Reviewers
• Anonymous Similar Reviewers

105
Group Lens Aggregate-based Filtering

• Multiple (arbitrary) people rate message
• Rating combined into one aggregate number
  specific to reader
• Correlation coefficient - CAB
• Sum (i 1 to n) ((Ai - Amean) (Bi - Bmean))
• ---------------------------------------------
• Sqrt ( (Sum (i 1 to n) (Ai - Amean)2) Sum
  (i 1 to n) (Bi - Bmean)2))
• Given set S of rating users, aggregate
• Sum (i 1 to n) (Bi - Bmean)CABi
• -------------------------------------- Amean
• Sum (I 1 to n) CABi

106
News Scaleable Architecture
read news
post news
How should this architecture be modified?
107
Group Lens Architecture
News Server
post news read news
post rating
read rating
News Client
Modified News Client
send rating
get rating
108
Getting Ratings Other Apps

• Incentive to review?
• Implicit review
• Track amt of read time
• Other apps
• Books
• Buying is strong endorsement
• Movies
• People?
• Multi-dimensional
• I like his reliability but you care about his
  creativity

109
Adding Agent-based Filters

• Spell checker
• Rating inversely based on misspelled words
• Included messages
• Rating inversely based on included text
• Length
• Rating inversely based on message length
• Agent is another user giving ratings!
• Can find correlation with an agent

110
Adding Filters
News Server
post news read news
post rating
read rating
News Client
Modified News Client
send rating
get rating
Only filterbots agreeing with user used in
ratings!
111
Adding Filters
Sarwar, Konstan et al 98
112
Evaluating Aggregation-based Filtering

• Coverage
• Measures of time predictions are available
  before an item is rated by user
• Based on a minimum of ratings available from
  sufficiently close neighbors
• Decision Support Accuracy
• Probability random good item rejected by system
• Probability random bad item accepted by system
• Good vs bad
• 4,5 vs 1,2,3

113
Experiments
Coverage, Decision Making Accuracy
114
Experiment Conclusions

• Net.general
• Filters hardly helped
• Perl.misc
• Spell helps a lot
• Others help somewhat
• Linux.Announce
• Length and spell help
• Recipes
• Spell checking helps
• Humor
• All factors but length help

• Spell helps
• Included messages
• Must be right amount
• Length useful in announcements

115
Annotated Files

• Discussions are like news
• Shared among n users
• Author name evident
• They are associated with shared objects
• UI for adding discussions
• Hypermedia vs. columnar UI

116
PREP Zero-Cost Hyperlinks
Main text
Alices comments
Benus comments
Chous comments
Para 1
117
Quilt Writeable Typed Hypermedia
Artifact Document Colab. Info.
In SharePoint now
Triggers Alert significant changes
Colab Styles Author modifies
owned section Co-author modifies all
Designated editor modifies all
Roles Reader lt Commenter lt
Co-Author
Fish. Kraut et al 88
118
Annotation Granularity

• Whole document
• Links to threaded discussion about it.
• Good for making broad comments
• preferred by readers
• Directly transferred from hard copies

• Parts of document
• Anchors to part of the document.
• Difficult to implement
• Do not require reproducing document part being
  commented.
• Good for detailed comments.
• In theory at least.

(Brush, Bargeron et al.)
119
Office 2000 Variable Granularity Annotations
(Cadiz, Gupta et al. 2000)
120
Office 2000 Study

• Specification Drafts rather than Completed
  Documents
• Ten month period.
• 20 annotations per person.
• Large fraction stopped after first annotation
• Orphan annotations losing context a reason

• Users do not make high-level comments
• Author would not get it
• Or nitpicky ones such as spelling, language
• Other readers not interested in them.
• Use other channels when immediate communication
  required
• Cannot assume notification subscription

(Cadiz, Gupta et al. 2000)
121
Orphan Annotations

• Users liked it when the differences between old
  and matched text was small but not large.
• Did not work well all the time
• Could match keywords instead of whole text.
• Could do an intelligent diff as in PREP
• Neuwirth, Chandok 92

• Arise when fragment to which anchored is deleted.
• Office 2000 attaches them to the whole document.
• Not ideal if no longer relevant
• More sophisticated algorithm
• Save deleted fragment.
• Find new matching fragment
• Cut words from back and front and do match.
• Stop when lt 15 chars to avoid false positive.

Brush, Bargeron et al 2001
122
Live Annotations?

• Nitpicky comments entered as edits.
• Special annotation right and view like read right
  and view in Office
• Shown as a track change.
• User can accept the underlying script.
• Akin to calendar invitations
• Email desired changes to shared artifact
• Dual
• Automatically email/notify actual changes to
  shared artifact

123
Automatic Notifications

• Content not given
• Changer does not know if manual email needed

124
Descriptive Notifications

• Actual comment given.
• Link to thread.
• Commenter knows subscriptions.

125
Mercury Automatic In-Place Notification
module A export T type T char
module A export T type T String
Asynchronous Error notification
Edit T
User 1
126
Subscription Mechanism
(Cadiz, Gupta et al. 2000)
127
Subscription Specifications

• Enrique Whenever any document is created inform
  him about it.
• Alice Benu Whenever any document is created
  inform them about it.
• Alice Benu When any document they own is
  modified, send them an event
• Chou Dimitri When any circulation document
  they have processed changes stations, send this
  event to them

128
GroupDesk Automatic Customizable Awareness
Notification
Relation Classes
Object Classes
Event Classes
WorksOn
Modification
Object
can establish
can raise
Document
Comment Added
Editor
Relations Editor Events Modification
Interested Users Alice, Benu
Interest Context
129
Event Semantics

• Interest context associated with object classes
• Relations implicitly defined by system
• Currently active user.
• Document creator
• When an event occurs on object
• For each interest context
• If event is subclass of specified event field
• Send event to all interested users who have the
  specified relation with the object

• Example 2
• Object Class CirculationDocument
• Interest Context
• Relation HasProcessed
• Event ChangesStation
• Users Chou, Dimitri
• Example 2
• Object Class Document
• Interest Context
• Relation
• Event Created
• Users Enrique
• Inherited by CirculationDocument

130
Disruption caused by notifications

• Czerwinski, Cutrell et al 2000
• For complex tasks
• No problems
• For simple tasks
• Performance went down
• Automatic prioritization useful
• Polling vs. notifications?
• Grudin 94 Managers who with staff polled
  calendar continuously found notifications
  nuisance

131
Side Show
(Cadiz, Venolia et al. 02)
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Side Show
(Cadiz, Venolia et al. 02)
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SideShow Peripheral Awareness

• Three level of awareness
• In sideshow sidebar
• In document from where ticket is moved.
• By hovering on sidebar
• Can be used for any information source
• Person
• Weather map
• Web page

134
Side Show Person Aawareness
(Cadiz, Venolia et al. 02)
135
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136
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137
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Talk File
Talk Mail File Talk File Talk Mail Mail
File Talk Mail File
141
RTCAL Real-Time Artifact Sharing
142
Scroll Wars

• User scrolling to see some pvt appointment causes
  scroll wars

143
GROVE Access-Controlled Views
User and State Awareness
No Concurrency Control
Incremental Sharing
Independent Scrolling
Outline Title 1. Readable and
writeable item 1.1 Also
readable and writeable .Shared readable and
writeable . Shared readable
Outline Title 1.Readable and
writeable item 1.1 Also
readable and writeable 2. A Shared Item
. Different shared item
User 2
User 3
User 4
User 1
User 3
User 4
User 1
User 2
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Cognoter (Stefik et al 85)

• Groove cannot scroll independently
• Keep pvt and public information in separate
  windows.
• Drag and drop or commit to make public a la IM
• Now scroll wars only occur in public window
• Ability to scroll together or separately
• Can also change scrolling mode in Groove
• Process model in shared window
• Brainstorming add items (ideas) to shared
  window
• Organizing collect ideas into alternatives
• Evaluation discuss and delete alternatives
• Analogous to SEPIA process model.

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Aspects Concurrency Control

• Groove user working independently must manually
  enforce CC
• Free for all
• Paragraph-level locking
• Adjacent bar gives lock status
• Black for locker, grey for others
• Medium mediation
• A pen passing mechanism ala Groove/NetMeeting
• Full mediation
• Moderator passes pen
• Conference starter is moderator

146
Interactive Lock Probelms

• Overhead in locking unlocking
• If explicit commands needed
• GroupDraw selecting/unselecting ? lock/unlock
• May forget to unlock

147
CES Delayed Commitment Tickle Locks
Tickle Locks (Timed out)
Distributed Document Nodes
Document Root
Implicit Commit Del/CR to unlock items
Text Node Owner User 1
Text Node Owner User 2
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Locking Delay

• Might need to go to remote site to determine if
  lock available
• Assuming lock information is not replicated
• Replication requires addressing consistency
  problems

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GroupDraw Virtual Gestures Optimistic Locks
Optimistic Locking
Coupled Graphical Objects
Implicit Locking/Unlocking
Uncoupled Scrollbars Palettes
Fine-grained CC AC
Multiuser Scrollbar Gestalt Viewer
User 2
User 1
150
Independent Drawing Modes

• GroupDraw allows users to select drawing mode
  independently
• What happens in single display groupware?
• Pebbles
• Mobile computer as input device
• Shared screen is output device

151
Pebbles Single-Display Groupware
152
Ensemble

• GroupDraw and Pebbles pointer exported to all.
• Ensemble selectively import and export
  telepointers.
• Implicit Session Management editing same file
  puts users in same session.
• Locked objects changes not broadcast.

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Talk Mail File

• Talk
• Mail
• File
• Talk Mail
• Talk File
• Mail File
• Talk Mail File

154
IRI Distance Learning Environment
Figure available at http//www.cs.odu.edu/tele/ir
i.