A holistic framework for evaluating virtual reality experiences.

VR relies on two fundamental pivots

Presence

a sense of being there

Authenticity

a sense of trueness and genuineness

Three primary influence factors

Static Factors
Dynamic Factors
Experience of Use
Gaming Experience
Mood and Mental State

User

Context

Environment Conditions
User's Surroundings
Purpose of Use

System

Hardware Capabilities
Network Efficiency
Tracking Accuracy
Latency Issues
System Reliability

Across three quality levels

Perceived Quality

Immediate impressions: vividness, enclosure, responsiveness, and presence.

Experienced Quality

The user compares system output with expectations, comfort, goals, and memory.

Judged Quality

Reflective evaluation tests plausibility, believability, coherence, and congruence.

Immersivity

The extent to which a user feels surrounded by and present inside a virtual environment — the foundational sense of "being there." Everything else in the taxonomy depends on this being sufficiently established.

What the system provides

Visual fidelity

Wide FoV, high pixel density, display resolution, and rendering quality produce richness and vividness that support perceptual absorption.

Tracking

Accurate position, orientation, gesture, and body tracking synchronize real movement with virtual movement and strengthen embodied immersion.

Persistence, latency, refresh rates

High persistence, latency, or low refresh rates introduce blur, lag, nausea, and break-in-presence risks.

Audio fidelity

Binaural, spatial, and ambient sound sources create aural envelopment and help the virtual world feel surrounding rather than screen-bound.

Headset types

Tethered, standalone, lightweight, occluding, or poorly fitted HMDs shape performance, isolation, comfort, and distraction.

What the user experiences

Presence

Users report feeling transported into another reality, engaging with objects and characters as if they were present.

Attention

External distractions fade, focus narrows to the virtual world, and time can feel compressed by sustained engagement.

Sense of embodiment

Accurate head, body, and motion capture can make the virtual body feel like the user's own body.

Connections

Poor tracking accuracy degrades Presence and cascades into Interactivity failures. Higher visual fidelity raises the Plausibility threshold downstream, i.e., more photorealistic environments are more vulnerable to plausibility failures. Explorability sustains Immersivity over time; without it, initial presence fades.

Quality function

Immediate perceived quality: the system must first facilitate immersion before the user can form a stable sense of being there.

Evaluation focus

Look for sensory enclosure, vividness, low discomfort, accurate sensorimotor coupling, and whether the user forgets the physical surroundings.

Assessment approaches

Objective

Measure hardware quality, resolution, PPI, FoV, frame-rate stability, latency, image quality, and spatial sound accuracy.
Use image quality metrics such as sharpness, contrast, color fidelity, PSNR, or SSIM where appropriate.

Behavioral

Analyze engagement, time spent with virtual objects, gaze behavior, and attention patterns.
Use interviews or observation to understand whether users behave as if the virtual environment is their operative reality.

Psychological

Use presence questionnaires, spatial awareness prompts, focus groups, and post-experience reflection.
Ask users to describe the strength, fragility, and moments of break in their sense of being there.

Physiological

Track presence-related responses such as pupil dilation, heart rate, and gaze.
Correlate physiological measures with self-reported presence.

Read the full paper →

Interactivity

The ability of users to interact with the virtual environment and influence their experience — the sense of control and agency. This is where the user stops being a viewer and becomes a participant.

What the system provides

Intuitiveness and responsiveness

Input delay, throughput, responsiveness, and clarity of feedback determine whether actions feel immediate and consequential.

Input modality

Gaze, laser pointers, controllers, hand tracking, natural gestures, and movement inputs must match the task and user capability.

Device and interface appropriateness

Ergonomics, usability, aesthetics, utility, and interface familiarity shape naturalness and satisfaction.

What the user experiences

User agency and control

The user senses ownership over actions and outcomes when the world responds clearly and predictably.

Ease of interaction

Simple, learnable controls reduce cognitive load and let users focus on the experience rather than the mechanism.

Cognitive adaptability

Interaction complexity aligned with user skill can support motivation, flow, problem solving, and sustained engagement.

Connections

Input latency feeds back into Immersivity, i.e., it can degrade presence directly. Agency and Naturalness condition Affect and Meaningfulness in Believability. The relationship runs in both directions: a believable narrative sustains motivation to interact even when interaction modalities are technically limited.

Quality function

Agency layer: the user moves from being transported into a world to being able to act inside it and understand consequences.

Evaluation focus

Look for meaningful control, task-fit between input modality and action, low cognitive load, and interaction methods that match user ability.

Assessment approaches

Objective

Measure controller responsiveness, interaction latency, input timing, and smoothness of virtual actions.
Use eye tracking or motion capture to capture input precision and response timing.

Behavioral

Measure completion speed, interaction accuracy, error rates, time to target, and gesture recognition accuracy.
Observe object manipulation, navigation patterns, points of frustration, and whether users understand interaction mechanics.

Psychological

Assess sense of agency, challenge, motivation, satisfaction, cognitive load, and perceived interface intuitiveness.
Use qualitative interviews to understand whether users felt empowered or constrained.

Physiological

Correlate muscle tension, heart-rate variability, stress, or workload markers with interaction complexity and performance.
Use eye tracking or brain-imaging-derived workload measures where the study context supports them.

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Explorability

The ease and degree of freedom with which users can navigate and discover new elements within the virtual environment. This dimension sustains presence over time — it is the primary mechanism that keeps a user inhabiting a virtual world rather than merely visiting it.

What the system provides

Degrees of Freedom

Higher DoF enables intuitive directional and positional tracking, increasing freedom while reducing disorientation.

Spatial resolution and loading times

World size, detail, and loading behavior determine whether discovery feels continuous or fragmented.

Navigation

Wayfinding and travel systems shape mental mapping, performance, presence, and sickness risk.

Locomotion

Room-scale, motion-based, teleportation, arm-swinging, and other techniques mediate movement perception and naturalness.

What the user experiences

Sense of expansiveness

A freely navigable world can produce discovery, awe, excitement, and temporary liberation from physical constraints.

Spatial awareness and understanding

Clear landmarks and layouts help users form mental maps and emotional attachment to virtual places.

Curiosity and intrigue

Accessible, discoverable corners invite users to seek out new spaces, events, and hidden elements.

Connections

Curiosity Satisfaction is the primary mechanism sustaining presence over time that feeds back directly to Immersivity. Locomotion depends on functional Interactivity QoS. Spatial coherence feeds forward into Plausibility whereby inconsistent spatial physics break logical congruence.

Quality function

Sustained presence layer: exploration keeps presence alive over time and begins to expose the world as coherent or incoherent.

Evaluation focus

Look for freedom, wayfinding, spatial memory, curiosity, navigational confidence, and whether the environment rewards movement.

Assessment approaches

Objective

Measure rendering speed, loading times, frame rate, object loading, and level-of-detail streaming efficiency.
Compare loading and navigation performance across hardware conditions.

Behavioral

Analyze navigation efficiency, task performance, dwell time, exploration paths, non-linear exploration, and navigational aid use.
Track areas explored, time spent in the virtual space, and responses to obstacles or unexpected events.

Psychological

Assess cognitive mapping, spatial memory, perceived freedom, control during exploration, and satisfaction with navigation.
Include emotional scales for curiosity, excitement, anxiety, and engagement.

Physiological

Measure stress during disorienting exploration, heart-rate variability across exploration phases, and skin conductance during discoveries.
Use facial expression analysis for joy, curiosity, frustration, or disorientation.

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Plausibility

The degree to which the virtual environment's rules, behaviors, and interactions align with the user's expectations and cognitive models. What's happening is real — or at least, it follows a consistent logic that makes it feel real.

What the system provides

Perceptual constancy

Objects should retain stable shape, size, position, color, and lightness despite environmental or contextual changes.

Aliasing and sampling

Jagged edges, pixelated textures, and visual discontinuities disrupt the credibility of the virtual environment.

Physics consistency

Gravity, collisions, kinematics, material behavior, and cause-and-effect chains must obey the world rules.

What the user experiences

Perceived congruence

The user can apply real-world or fiction-world knowledge because objects and events behave consistently and naturally.

Alignment and prior knowledge

Plausibility strengthens when behavior resonates with the user's mental models, experience, and expectations.

Cognitive dissonance

Unexpected, illogical, or contradictory events create discomfort and can undermine presence and enjoyment.

Connections

Plausibility is downstream of all three Presence dimensions. Sensory fidelity, interaction consistency, and spatial coherence must all hold for logical congruence to emerge. A failure here is the primary mechanism that shatters Believability.

Quality function

Authenticity as trueness: plausibility is syntactic and tests logical congruence between the virtual world and expected rules.

Evaluation focus

Look for stable rules, physical consistency, sensory alignment, predictable cause and effect, and moments where the world stops making sense.

Assessment approaches

Objective

Evaluate object interaction consistency, physical rules, logical contradictions, sensory alignment, collision behavior, and gravity simulation.
Use quality metrics for 3D models, physics simulations, and affordance mismatches.

Behavioral

Observe adaptation to plausible versus implausible scenarios and track trust in the world's rules.
Measure object interaction frequency and accuracy to detect affordance mistakes.

Psychological

Use questionnaires on realness, object permanence, predictability, and adherence to user expectations.
Capture emotional responses to nonsensical events, confusion, frustration, amusement, or broken logic.

Physiological

Measure confusion-related brain activity or changes in muscle tension during unexpected occurrences.
Relate physiological surprise or unease markers to specific plausibility failures.

Read the full paper →

Believability

The degree to which the VR experience delivers the internal coherence, narrative logic, and emotional resonance needed to sustain suspension of disbelief. If it is convincing, it is happening. This is the most emergent and most fragile dimension — the consolidated judgment of everything that preceded it.

What the system provides

Visual representation

Rendering quality, physically based materials, asset geometry, and visual cues shape perceived realism.

Audio synchronization

Sound timing and spatial location must match virtual distance, location, and event timing.

Internal coherence and consistency

Physics, interactions, characters, story logic, style, and tasks must fit together within the established world.

Atmospherics and randomness

Imperfections, nuanced reactions, environmental detail, and character animation create naturalness and world texture.

Scenario logic

Scripted events, narrative complexity, predictability, meaningfulness, and decision-making support cognitive absorption.

What the user experiences

Suspension of disbelief

Users willingly accept the virtual environment as real enough despite knowing it is artificial.

Narrative and emotional responsiveness

Investment in characters, situations, and story produces emotional resonance and loss of time awareness.

Social presence

Believable agents or other people can create genuine connection and a sense of being inside a living world.

Prior VR experience

Experienced users may have sharper expectations, while imagination and suggestibility can increase acceptance of fictional worlds.

Connections

Believability depends on all four preceding dimensions. It is easier to destroy than to build. In other words, a single Plausibility break can shatter it entirely. Its bidirectional loop with Interactivity is notable: a believable narrative sustains interaction motivation even when technical quality is limited.

Quality function

Authenticity as genuineness: believability is semantic and depends on internal coherence, emotional resonance, and suspension of disbelief.

Evaluation focus

Look for narrative logic, atmosphere, meaningfulness, social connection, emotional investment, and whether users accept the world on offer.

Assessment approaches

Objective

Benchmark asset quality, animation fluidity, environment size, object density, texture detail, dynamism, and environmental audio.
Review ecological realism, narrative structure, character realism, and world complexity.

Behavioral

Track user choices and reactions to character actions, plot events, and world rules.
Analyze whether user decisions are driven by the perceived logic and stakes of the virtual world.

Psychological

Assess narrative absorption, fictional immersion, emotional impact, character connection, and suspension of disbelief.
Use self-report and qualitative analysis to understand empathy, affect, and meaning.

Physiological

Measure startle responses, heart-rate spikes, and electrodermal activity during suspenseful or emotional moments.
Cross-reference emotional physiology with facial expression or narrative-event analysis.

Read the full paper →