Heim's discussion of immersion encompasses much more than I ever thought virtual reality would encompass. I understood that there can either be total immersion or partial immersion, and Heim gives examples of each. For instance, HMD or head-mounted display is an example of full or total immersion in which a person straps on a helmet with an LSD screen as well as audio, allowing the wearer to experience VR. CAVE, another type of total immersion utilizes an enclosed room where a person could basically walk around the virtual world. Many people don't have access to these forms of full immersion, but they may experience partial immersion through simulation and telepresence such as having a phone conversation. The movie theater experience may cause a viewer to be partially immersed and possibly even fully immersed.
In fact, I've experience partial immersion at the movie theater. At Disney World, I watched a 3-D show of Honey, I Shrunk the Audience, and I screamed because it seemed as if mice were crawling on the floor, a dog sneezed on the audience, and a snake was going to attack. It felt real although I knew it was fake. One question I have though is about dreams. Although there is no "technology" behind them, could a dream be considered VR? I've had and undoubtedly some of you have also had those dreams that feel so real and seem as if you're totally immersed; the scenes are so life-like; you can make out certain fragrances; there are restrictions just like in real life. So, if you're totally immersed in a dream, are you experiencing VR per se?