Measuring and Transforming the Believability of Embodied Agents

Jeremy BailensonDepartment of Communication

Stanford University

Virtual Human Interaction Labhttp://vhil.stanford.edu

Overview

• Metrics of Copresence (Believability): Theories, terms, empirical examples

• Quick Revisit to the Uncanny Valley

• Strategic Transformations of Agents:– “Augmented Social Interaction”

Copresence

• What is it?– Is that virtual human perceived as if it were a physical

human?

• Is it measurable?

• Synonyms: Social Presence, Believability, Engagement, Rapport, Interactional Synchrony

Current Methodology:Questionnaires

• Questionnaires 95 percent of copresence research

• Problems with Questionnaires:

– Ambiguity:

"How much did it seem as if you and the other people both left the places where you were and went to a new place?“

- Demand Characteristics

- Implicit/subconscious

How do you measure copresence?Questionnaires (95%) cheap and easy

Open ended interviews

Physiologically (brain activity, heart arousal, skin conductance)

Memory for objects in VR (compared to physical space)

Presence as absence (in VR does the physical world disappear)

Behavior (do in VR as people do in physical space: nonverbal behaviors, learning, physical reactions, etc.)

Today: Proxemic behavior, Eye Gaze, Disclosure, Turing Tests, Learning

Social Presence and Proxemics

Proxemics Background• Studied extensively in psychology and

anthropology since 1950’s

• Equilibrium Theory (Argyle & Dean, 1969)

– NVB’s trade off– Predictions in regards to proxemics

• Do proxemics patterns hold true with virtual people?

Sample Proxemics Task

Sample Data

CONTROL CYLINDER

COND 1 EYES CLOSED

COND 2 EYES OPEN

COND 3 BLINKING

COND 4

BLINKSAnd

HEAD TURNS

COND 5

BLINKS,HEAD TURNS,

AndPUPIL

DILATION

Equilibrium: Personal Space and Gaze

In the “Real World”: Second Life

Personal Disclosure (verbal and nonverbal)

Show movie

Eye Gaze as Copresence Proxy

TSI: Detection: Nonverbal Turing Test

Learning

Uncanny Valley Revisited

Static Low Medium high

Block N >20 N >20 N >20 N >20

Bear N >20 N >20 N >20 N >20

Human N >20 N >20 N >20 N >20

Head Movement RealismMeasures:

Subjective RatingsGaze/Head MovementsMemoryProxemics

Transforming Agents to be Effective

(Believable?)

Collaborative Virtual Environments

Transformed Social Interaction (TSI)

ActualBehavior

StrategicFilter

TransformedBehavior

3 Dimensions of TSI

• Transforming Self Representation

• Transforming Social-Sensory Abilities

• Transforming Social Context

TSI: Augmented Gaze• Gaze is powerful:

– Learning (Sherwood, 1987)

– Persuasion (Morton, 1980)

– Physiological Arousal (Wellens, 1987)

– Shaping the structure of a conversation (Kendon, 1987; Argyle, 1988)

TSI: Augmented Gaze

TSI: Digital Chameleon

TSI: Digital Chameleon

• Persuasive passage read by Agent

• 60 subjects– Mimic (4s lag)– Recording of other

subject

TSI: Digital Chameleon

TSI: Facial Identity Capture

TSI: Identity Capture

• Similarity among people results in:

– Attraction (Shanteau & Nagy, 1979)

– More Persuasion (Chaiken, 1979)

– More purchases (Brock, 1965)

– More altruistic helping behavior (Dovidio, 1984)

– Trust (DeBruine, 2002)

Facial Identity Capture:High Info, Familiar Target

• National random sample (N = 200)

• 1 Week before presidential election

• Viewed candidate photos while evaluating Bush and Kerry

• 3 groups of subjects– No morph– Bush Self, Other Kerry– Kerry Self, Other Bush

TSI: Facial Identity Capture

TSI: Facial Identity Capture

The Virtual Mirror

The Proteus Effect

Learning: Augmented Social Perception

T

Learning: Transformed Proximity

Learning: Virtual Knockout

Ethics

Collaborators

Megan MillerAndrew OrinNicole LundbladJulia HuClaire CarlsonAaron SullivanBoyko KakaradovHassan Adubu

Stanford Graduate Students/Post Docs

Nick YeeDan MergetManos PontikakisKayur PatelRobby RatanHunter Gehlbach

Stanford Faculty

Shanto IyengarCliff NassRoy Pea

Byron ReevesDan Schwartz

UCSB Faculty/Post Docs

Andy BeallJim BlascovichJack Loomis Matthew Turk

Rosanna Guadagno

Thank you!

Virtual Human Interaction Labhttp://vhil.stanford.edu

Josh AinslieAdrian De La MoraJon ShihJaireh TecarroSam WarburgKathryn RickertsenJerry Yu

Stanford Undergraduates

Berkeley Faculty

Ruzena BajcsyJaron Lanier

Applications

• Learning

• Communication Technology

• Advertising

• Politics

Face to Face TSI?