CS260 Lecture 7 Professor John Canny 2/24/2019

Computer-Mediated Communication Communication involves at least two people. What are their respective goals? 2/24/2019

Electronic Media vs. Face-to-face Knowledge workers have a host of electronic media available, but still travel across town or across the country for face-to-face meetings. Why? 2/24/2019

High-stakes communication What were the most important communications you have had in the last several years? 2/24/2019

Media richness (Daft & Lengel) Match the affordances of the medium to the communication task. High richness (often high stakes) Face-to-Face Ambiguity, ephemeral, expressive Video-conf? Telephony IM Clarity, recording, constraint Email/memos Reports Low richness 2/24/2019

Media choices in the workplace For routine business communication, we surveyed users about their choice of media: Email Instant Messaging Telephony Face-to-face There was one medium that rated higher under several criteria. What do you think it was? 2/24/2019

Non-verbal communication In real life, we use a lot more than speech (or sign language) to communicate. Non-verbal communication includes: Gaze, eye contact Facial expression Gesture Posture Touch Location (proxemics) Time Prosody (speech) 2/24/2019

Non-verbal communication Which of these cues are preserved by: Email? Instant messaging? Telephony? Video-conferencing? 2/24/2019

Non-verbal communication Q: What is the role of these cues in normal communication? A: It depends totally on the role of the communication, e.g. Routine (giving information, coordinating) Persuading and being persuaded Trust, deception and negotiation … 2/24/2019

Routine communication Most of what happens in most organizations. Doesn’t seem to benefit much from non-verbal cues, and in fact there is evidence that people prefer less-rich media such as email and telephone: Sproull and Kiesler: computer science students did better with email than face-to-face meetings. Connell et al.: Business employees preferred the phone over face-to-face and email for routine communication. 2/24/2019

Persuasion Seems to be strongly influenced by gaze and facial cues (Werkoven et al.). Note: Most non-verbal cues are not consciously processed. We transmit and receive without being aware of what we are doing. Most non-verbal cues are strongly influenced by our personality and emotional state. Facial expression is different however. We consciously manage it, and it shows very little correlation with emotional state. 2/24/2019

Trust and deception Most people emit easy-to-read non-verbal cues when they try to deceive. These are the basis of “lie detector” tests. They include: Prosodic speech variation Skin conduction (due to sweating) Breathing and heart rate changes Particular body gesture cues 2/24/2019

Trust and deception Facial expression on the other hand, since it is consciously managed, is a poor cue to deception. Most deception cues therefore, are “below the neck”. 2/24/2019

Trust and deception A former president: 2/24/2019

Trust and deception A former president: 2/24/2019

Trust and deception A former president: 2/24/2019

Gaze distortion Its physically impossible with standard video displays to preserve gaze for a group of people on either side of a video connection. Unfortunately, that is the most common case in commercial settings. B Make text bigger Mehrabian’s findings could partially explain what’s going on here. Bos’ Paper Measure development of trust in group settings NOT DYADIC Trust is widely applicable Groups communicated using one of four different communication channels Text Voice Voice+Video FTF Trust was measured using a Daytrader game (variant of prisoner’s dilemma) Findings In FTF, high level of trust immediately attained and maintained through the game Delayed Trust – Audio/Video channels required some amount of time before achieving FTF level of trust Fragile Trust – Those using Audio/Video had a higher likelihood of someone defecting No significant different in trust development patterns when adding a video channel What are the factors that caused there to be no effect when adding a video channel? How do we address these factors? A 2/24/2019

Gaze distortion Only A believes that the other person is looking at them! This is because of the Mona-Lisa effect. B Make text bigger Mehrabian’s findings could partially explain what’s going on here. Bos’ Paper Measure development of trust in group settings NOT DYADIC Trust is widely applicable Groups communicated using one of four different communication channels Text Voice Voice+Video FTF Trust was measured using a Daytrader game (variant of prisoner’s dilemma) Findings In FTF, high level of trust immediately attained and maintained through the game Delayed Trust – Audio/Video channels required some amount of time before achieving FTF level of trust Fragile Trust – Those using Audio/Video had a higher likelihood of someone defecting No significant different in trust development patterns when adding a video channel What are the factors that caused there to be no effect when adding a video channel? How do we address these factors? A 2/24/2019

Mona Lisa Effect In this slide, we simulate different perspective by virtually rotating the mona lisa. For each rotation, we grab an image of only the face (to remove the context of the perspective lines. We see that viewing at 0 and 50 degrees still looks like she’s looking directly at us. There is only a transformation in the horizontal direction. Sometimes known as horizontal parallax 10 20 35 50 2/24/2019

Solutions Props (mobile presences) address some of these issues. They even support exploration. 2/24/2019

MultiView Display 1 2 3 Line up rays with eyes. Light is retroreflected toward the source in the horizontal direction. Each user has their own projector, sees their own image. 2/24/2019

MultiView Directional Display Each view is provided by a projector The projected image is reflected directly back in the direction of the projector The image can be seen at varying heights only behind the projector Each user gets video from a unique camera at the other end. The MultiView display is a multiple element screen. Each view is provided by it’s own projector. The image from the projector is reflected directly back in the direction of the source in a way that the image can be seen at varying height behind the projector. 2/24/2019

Cameras Projectors MultiView Display 2/24/2019

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1 2 3 2/24/2019

MultiView Display The Multiview design fully preserves gaze cues between all pairs of participants, on both sides of the connection. It also reproduces everything that’s visible above the table at the other end (same deception cues as a face-to-face meeting). Goal is to see if we can reproduce persuasion and trust cues. The MultiView display is a multiple element screen. Each view is provided by it’s own projector. The image from the projector is reflected directly back in the direction of the source in a way that the image can be seen at varying height behind the projector. 2/24/2019

CSCW Evaluation Evaluation of CSCW systems is difficult because of: Logistics of data collection (separated in time and space, and huge). Number and complexity of variables. Validating re-engineered group work. 2/24/2019

Logistics of data collection Suggestions? Get partners for other locations Self-reports Instrument! – record everything in the system Video – get if at all possible Get context information 2/24/2019

Number and Complexity of Variables Suggestions? Start with some hypotheses – but keep eyes open Iterate on experiment design Keep user tasks simple – caveat about considering entire cooperative activity 2/24/2019

Validating re-engineered group work Suggestions? Long-term evaluations Co-evolutionary design 2/24/2019

Livenotes: Collaborative Note-taking Pen and keyboard input Unique user color Import background slides Small peer group Group awareness Pages that users are on The UI that was developed in Java. Performance issues with Clios as we added more features. Notebook metaphor Shared whiteboard 2/24/2019

Client-Server Topology Group 1: Server 802.11b networking Large class broken down into many small groups (3-7 students) One Tablet per group is set to server mode Other members’ Tablets connect wirelessly to group’s server Clients … Group n: The UI that was developed in Java. Performance issues with Clios as we added more features. Server Clients 2/24/2019

Experiment Spring 2003 undergraduate HCI class 21 volunteers, randomly partitioned into Cooperative note-takers Individual note-takers (control group) 4 weeks (7 lectures) Preloaded skeletal PowerPoint slides 2/24/2019

Previous Observation From previous deployments, we learned that Undergraduates were not used to discussing lecture material with one another Graduate students engaged in group discussions spontaneously Required students to do these face to face discussions to stimulate on-tablet discussions For this experiment (with undergraduates), we held short, live group discussions in the classroom 2/24/2019

Cooperative Note-Taking: Richer Notes Average cooperative note-taking group took more than twice as much notes as individual note-taker. Average cooperative note-taking group has more commentary, question and answer, and reinforcement marks (46.4%) than individual note-taker (7.6%), above simply note-taking 24.6% of marks attributed to group interaction Make the connection to hypothesis #1. 2/24/2019

Cooperative Note-Taking: Richer Notes 2/24/2019

Augmented Note-Taking: Observed Behaviors Elaborated on bullets Appended bullets to list Concurred and disagreed with bullet Noted gist of HCI principles Noted advantage and disadvantage of HCI technique Answered questions in bullets 2/24/2019

Elaborating on Bullets 2/24/2019

Appending Bullets to List 2/24/2019

Answered Question in Bullet 2/24/2019