I agree with Murray's suggestion that digital environments possess four essential properties; procedural, participatory, spatial, and encyclopedic. I also agree that procedural/participatory properties create the interactivity we experience and that spatial/encyclopedic create an environment which is as "explorable and extensive as the actual world" in other words an immersive environment. However, I think that each of these four qualities needs to be defined further in order to better understand their relationship to the user. Separating the computer's properties from the human experience helps us to further understand these properties and augment the number of essential properties that Murray suggests in Chapter 3.

Procedural properties suggest structure, sequential processes and a linear format--they are created by the computer's procedural programming. While participatory properties--a result of this programming--create the interactivity experienced by the user. In order for a digital environment to be participatory it must be responsive to the user's input. This responsiveness/input modifies the original environment creating a digital environment which continually evolving.

Spatial properties suggest a way to visually navigate/travel through a system--they are also created by the computer's programming and for the most part the user is unable to modify their constructs. However, they too are responsive to the user's input. For example, the game Myst enables users to navigate through an environment much like RL but you can only select from a few navigable options such as go west, east, north or south. In RL I can choose to navigate in many diverse directions. I believe spatial properties are much like the procedural/participatory properties only more visually expressive of a RL environment.

Encyclopedic properties suggest total chaos if the site's navigation isn't well organized. Murray states, "The conventions of segmentation and navigation have not been established well enough for hypertext in general, let alone for narrative. The separation of the printed book into focused chapters was an important precondition of the modern novel; hypertext fiction is still awaiting the development of formal conventions of organization that will allow the reader/interactor to explore an encyclopedic medium without being overwhelmed." The mapping of information is an important feature of any Web site and can add to the interactive experience by creating a sense of understanding and accomplishment when you quickly find desired information. This positive experience also fosters a repeating/revisiting pattern, where users begin to depend on a site for its features. I believe the organization/structure of the site's information should be the first design considerations when creating a Web site--it's the basis for making a site more understandable and navigable. How many times have you left a site because you couldn't immediately understand what is was about?

I would recommend adding responsive, evolutionary, understandable, navigable and dependable to the four qualities Murray suggested.

Below are examples of Murray's 4 essential properties of the digital environment as well as examples that support my own recommendations:

PROCEDURAL Amazon

PARTICIPATORY : SPATIAL Dragon Realms Dragon Realms is a MUD-style fantasy game where players teach other, explore a vast world, and slay monsters.

ENCYCLOPEDIC The Library of Congress

RESPONSIVE The Burn Barometer Enter the amount of time that you spend doing an activity and calculate the you've burned.

EVOLUTIONARY Descendants of the Shoah

UNDERSTANDABLE : NAVIGABLE MoneyMinded

DEPENDABLE Lycos Pittsburgh Weather