Immersive Design Reader - Glossary / by Will Cherry

As you read this Reader (and as I write it), you may come across some terms or acronyms I use. The majority of them are coined from the embrace of the immersive community or academic sources. Their definitions may change over time, and I’ll add more terms periodically. For now, let’s cover the basics. A hefty portion of these terms are also found in the No Proscenium Glossary.

180-Degree Rule— In filmmaking, a basic guideline regarding the on-screen spatial relationship between a character and another character or object within a scene. By keeping the camera on one side of an imaginary axis between two characters, the first character is always frame right of the second character. This is not primarily used in immersive work, but important to note for any 2D representation.

Activation — a location-specific temporary event, usually meant to cater to an audience familiar to a “world” from another media type. Common activations are for films, games, and fan events, and usually rely on immersive design for mass participants per hour.

Affordance— The ability for a participant or player to perform actions granted by a worldbuilder/developer through learning constraints. Or, an action perceived by the participant as possible by design. e.g. a door affords being opened, and a button affords pushing it. See also interactivity and agency.

Agency— In the immersive context, the ability for a participant or player to influence the world they inhabit. Agency can stretch from minor choices to major narrative decisions, and is the backbone to interactivity.

ARG/ARX — Alternate Reality Game/Experience. This type of experience blurs the border between everyday life and a generated playspace— where gameplay or narrative elements (either practical or digital, local or online) are presented as if they were real, and players are encouraged to “find the adventure in their backyard.” ARGs are intricate, but powerful for engaging a curious audience. For more reading on the intricacies of ARGs, please read mastermind Henry Jenkin’s blog!

Augmented Reality (AR)— Using technology or illusion, the addition or supplementation of sensory stimulus. Most AR applies to visual supplementation (handheld-device AR, headset displays or glasses-like screens that project images into your field of view), while some are auditory. Other senses can also be added (Olfactory/Smell, Somatosensory), usually at a larger scale (i.e. theme parks and casinos).

Continuity— In filmmaking, this is the progression of scenes or shots that feel like a natural progression of time or states. In storytelling work, we aim for the Illusion of Continuity, allowing a player or participant to feel that their low level actions contribute to a larger, high-level narrative.

Engagement— The consumption of an individual's mental bandwidth via an immersive experience, without the direct physical impact/input of said individual. e.g. watching football, television, reading, or traditional theater.

Escape Room — A thematic space that invites participants to solve various puzzles in order to progress to a finish within a time limit. While “Escape” is usually implied as the goal, other types of puzzle-based cooperative spaces fall under this category. Most popular escape rooms use premium production design, narrative, and game tropes to encourage teamwork and engage participants.

Experience — a catch-all term for immersive work whether it involves a narrative or not. This term can be tossed around quite a bit, but at its core, it can be defined as a timeframe in which an individual or group takes part in something unusual or extraordinary. Immersive and Experience designers make experiences; but experiences can generate themselves (Visiting a foreign country, the Grand Canyon, or skydiving are all unusual or extraordinary in their own right).

Horizon of Action— in a phasespace, this the collection of all possible actions a player/participant can make. In chess, this is considered all possible moves in a given turn. Term accredited to Brian Upton from The Aesthetic of Play.

Horizon of Intent— in a phasespace, this the collection of all actions a player/participant is aware they can make. Usually, this collection of actions is smaller than the Horizon of Action. A good Horizon of Intent should be interesting, by providing choice, variety, consequence, predictability, uncertainty, and satisfaction. Term accredited to Brian Upton from The Aesthetic of Play.

Hyper-Reality— coined by The Void, a Virtual Reality with a physically-built self-contained area. Audience members traverse a stage while wearing VR equipment that alters their perception of the set pieces and props, using a small set of objects, obstacles, and other effects to create the illusion of a world larger than that on the stage. This term isn’t used often, but is considered lexicon. Not to be confused with the brilliant short film HYPER-REALITY by Keiichi Matsuda)

Head-Mounted Display (HMD)— A device worn on a user’s head that shows visual and (sometimes) plays auditory stimulus. These displays can be classified as VR, MR, or AR depending on the design, but the roots of the term come from CRT and LCD displays in front of the eyes.

Immersive Theater— Unlike traditional theater or Theater in the Round, Immersive Theater requires an audience. It is an immersive art form where human performance and interaction with an audience is paramount, as the audience’s presence in each scene is influential in the narrative in some way (however minimal). Usually, Immersive Theater requires participants to navigate spaces or engage actors directly.

Immersive Senses— The senses used by an audience or user in a realitative platform, and the senses best manipulated by immersive designers. They are described as Sight, Sound, Savor, Somatosensation, and Social Behavior.

Installation — A physically-built element or enclosure for various forms of artistic expression. Installations are used in theatrical, artistic, and immersive work to physically separate a world-space from real-space, set tone, and direct participants.

Interactive— an experience that gives some degree of agency (or the illusion of agency) — to members of the audience. Follows the sense of “interactive cut-scene” as used in video games.

Involvement— The consumption of an individual's physical bandwidth via an immersive experience, where their actions and feedback from those actions create an immersive state. e.g. traditional videogames, sports, fitness, and riding a bicycle.

Mixed Reality (MR)— Popularized by Microsoft for their VR hardware, MR is a difficult term to pin down. Traditionally, MR is best defined as a supplementation of digital material into a user’s physical space. This muddles the water between VR and AR, so for this reader I will specify that Mixed Reality in this sense is a removal of traditional stimulus, replaced with an altered reprojection. An example of this is Pass-Through HMDs which use internal device cameras to capture outside the headset and combine the video feed with digital material.

That being said, Mixed Reality is morphing into a term for high-end AR, as Magic Leap describes their AR technology as Mixed Reality. If there's any definition changing in this glossary, MR is the one.

One-on-One— In Immersive Theater, a scene in a multiple-participant experience that features a single actor and a single audience member. (In Britain this is known as a “one-to-one.”)

Openframe — A term coined by director Mikhael Tara Garver in a series of essays meant to embrace the spectrum of productions (site-specific, promenade, installation, and immersive) which are often grouped together under the label of “immersive” work.

Pass-Through HMD— Not very popularized, but a version of VR head-mounted display (HMD) that uses cameras on the front of a headset to simulate human vision. Material projected to the screens inside the HMD for the viewer can be modified into a form of pseudo-VR, Mixed Reality.

Peter Pan Principle— Coined by Carrie Heeter in 1995, this principle applies towards Presence felt by the general public when in second-person virtual reality. In her experiment, around 25% of subjects easily felt presence, 50% somewhat felt presence, and 25% could not feel presence at all. "Once you make the initial leap, reality becomes plastic and you can fly."

Presence— The illusion that one is physically, and emotionally, in another space. This can be a fictional space, or a recreation of an actual space. Also: A sense of being somewhere or someone.

Readability— The ability for an experience to telegraph to a participant what they can/cannot do, and how their actions provide feedback. In game design: The quality of giving visibility to player choice.

Realitative— Of, relating to, or marked by reality. Also, capable of the state of being real. A platform or medium can be realitative if it pertains to reality and the bending/breaking of such. Coined by Will Cherry (I’m sorry).

Sandbox — from “sandbox video game.” An environment that encourages participants or players to explore new types of gameplay and narrative using tools provided to them. For Immersive theater, the tools are usually movement. For video games and simulators, Sandbox tools depend on context but allow for numerous combinations. (See: Universe Sandbox, Rec Room, and Garry’s Mod)

Savor— An Immersive Sense, combining the human biological senses of taste and smell that an audience or participant uses to observe flavor. Savor can be manipulated to spark memories, feelings, or evoke atmosphere for an audience.

Sight— An Immersive Sense, the human biological sense of vision using the eyes to receive wavelengths light, and the brain’s understanding of those wavelengths into meaningful information. This sense is manipulated by designers in various ways through media since art first existed.

Sound— An Immersive Sense, the human biological sense of hearing through the ears a range of frequencies usually above a certain level. Sound is manipulated in various mediums but is most powerful when configured to an individual’s Head-Related Transfer Function (HRTF).

Social Interaction— An Immersive Sense that isn’t tied to a human mechanical sense but rather a collection of mental states brought about by an individual’s self-projection in modern human society. How humans react to the various social presence of other characters (or lack thereof) in various environments is key to designing for realtitative platforms.

Somatosensation— An Immersive Sense, combining the human biological senses of mechanoreception (touch) and proprioception (body and spatial awareness). This sense can be manipulated by designers using Haptics, frequency audio transducers (ButtKickers), or custom physical set pieces to aid in the immersion of a work.

Spatial Computing— Publicly defined by Simon Grenwold (and others) of MIT in 2003, Spatial Computing has taken on a breath of new life since considered the new AR computing platform by Magic Leap. He defines it as “human interaction with a machine in which the machine retains and manipulates referents to real objects and spaces.” Magic Leap goes further to imply that computations of the machine do not have to have a local source (wearable hardware) but that processing will rely in Edge Computing. Regardless, it is considered a a future technical blanket term for AR, VR, and MR and a framework for tech-based realitative platforms.

Spatialized Sound— The placement of sound around an area to simulate a soundscape that envelops the participant or participants. Commonly, Spatialized Sound applies to 360 Video, VR, and AR as a form of direction and world-building.

Throughput — the number of patrons that can be accommodated in an instance of a production or experience. Often expressed as a function of guests per hour. In theme park ride design we call this THRC, or Theoretical Hourly Ride Capacity.

Virtual Reality (VR)— The removal of sensory input, and the supplementation of new stimulus to simulate another environment. This is commonly done with Head-Mounted Display (HMDs) and headphones, although other sensory input can be altered.

XR (Cross Reality or Extended Reality) — A catch-all term for VR, AR, MR, or other digital realitative platform. XR covers play spaces made primarily with digital tools.