Extreme deviation from real scale weakens presence

What it is

Shrink a person to pawn size inside a model of their own living room and presence flips from “in the room” to “looking at a model.” Once environmental scale departs extremely from the body’s habitual real proportion — the whole world a dollhouse, or the self an ant — “I am in this place” is replaced by “I am looking at a model / I am looking at a monument.” What weakens is presence, not whether size is estimated accurately.

Mild scale error is digested. Cross an order of magnitude and digestion becomes a break.

Why it happens

Presence depends on bodily scale expectations being met by the scene: the length of a step, the height of a door, a table edge within reach, all should land in the habitual range. Extreme minification keeps disparity and motion parallax in relation, but reachability, spatial falloff of sound, and the density of surfaces swept by a head turn no longer feel like “a place I can enter.” Extreme magnification turns nearby objects into terrain, and the spatial frequency of the ground drops below what the body will use as a floor.

The tell is often not “I cannot compute the metres” but a shift of person: from first-person “I am here” to third-person “that is a sandbox.” If the self-avatar is still adult-sized and the world is a toy, people protect the avatar’s scale and judge the world a model. If avatar and world both shrink, presence can sometimes hold — relative scale remains, the whole set is smaller. What actually hurts presence is environment scale relative to the body going extreme.

Studying it

Compare IPQ or SUS presence on a 1:1 scene, a scene minified by an order of magnitude, and one magnified by an order of magnitude, with tasks still completable (look, point, say “am I inside”). Also take free reports for person and metaphor (“model,” “monument,” “room”). Size-estimation tasks are a confound here: some people estimate accurately and have already broken presence; some estimate wrong and still feel there.

Manipulate environment scale relative to the body, not a few-percent eye-height tweak. That tweak belongs to distance perception, not to extreme deviation.

Where it stops holding

When the content is selling model-ness — a sandbox briefing, massing studies — extreme minification is the point, and presence is traded for mastery over a model; this “weakening” is not a defect. Dreams and wonderlands in narrative can use extreme scale to break on purpose. A short scale journey (a few seconds of shrink animation) lets presence rebound; a long stay at extreme scale kills the rebound. With no avatar and no visible hands, people accept extreme scale more easily, because a bodily ruler is missing to expose it. Children’s body scale makes “extreme” relative to adult scenes a different number.

Applying it

• For experiences that promise being-there, keep environment scale near one times bodily habit. When an overhead view is needed, use a miniature people can enter and leave; do not leave them in the dollhouse for the whole beat.
• If extreme scaling is required, change scale relative to the body together (avatar, step length, grasp radius). Do not put an adult hand into an ant world.
• Use an explicit transition in and out of extreme scale, and on return to 1:1 give a body referent (a door, the user’s hands) to recatch presence.
• How to check: spend a few minutes in the same room at 1:1 and at ten-times smaller, and ask “are you in the room or looking at a model.” A stable “looking at a model” in the latter means extreme scale has already swapped presence for observation; do not try to fix that with lighting.

Related

• Same group: N4.08.1 Without a known-size referent, vision alone cannot judge absolute scale · N4.08.2 A world miniature lets people operate a large environment from a god view · N4.08.4 Scaling the self turns far-field operations into near-field ones · N4.08.5 Once scale is established in a scene, it keeps biasing size judgments of new objects · N4.08.6 Virtual scale changes perception of distance and of one's own size · N4.08.7 Inconsistent scale breaks action expectations
• Nearby: N1.01 Immersion and Presence · N2.04 Direct Grab
• Search terms: environmental scale · presence and scale · dollhouse effect