I share Patrick Lichty's feelings (Note 23.8) that some topics of DMP study are not "media." My own motivation is born not so much of despair that some media pass out of use (I wish the chain letter would die already), but in relation to my profession, which we call at my company "media engineering".
So what is a "medium"?
Media mediate. Mediation is done "in the middle," as etymology will indicate. Media connect endpoints == they allow their subject to "move" between two endpoints. The subject can be elemental (non-reducible to components with different characteristics in the terms of the medium), or the subject can be another medium. The former is currently called "content"; the latter enables the "medium transmitting the medium" to be called a "metamedium".
Some media are communications media, the primary subject of inquiry of the DMP. These media transfer symbols, encoding messages between endpoints. Symbols may be encoded in hierarchies, so that a message can be a medium for another message. Network technology is rife with this kind of structured communication, so that the message you are now reading on this list is encoded in a nested series of symbolic levels.
The most "immediate" (pun and etymological apropriateness intended) symbolic level might be "email," depending on what you are using to decode this message. "Meta" levels contained in the structure of this message include ASCII and "English text". Meta levels that contained this message before it was decoded by your communications devices include MIME "text/plain," SMTP, and TCP/IP.
Other media are transport media, typically for passengers or freight. These media may also carry other media, as ships carry containers which carry boxes which carry ethernet cards, wire and routers. Sometimes these transport media die == ancient Greek amphorae are probably "dead transport media," as their pointed bottoms are best suited to their "metamedia" of ancient Greek barges, with their "pointed" holds.
Some artifacts that are related to media are confused with media, but are not themselves media. A good test to determine that an artifact is a "medium" is twofold. What does the putative "medium" mediate (what is its message, or subject), and twixt what does it mediate? Some recent DMP list postings, while interesting, fail this test.
The astrolabe, for example, might (in a precious argument) mediate between the constellation and the astronomer. But what does the astrolabe mediate? Perhaps "the configuration of the stars and the earth/observer," or "the observer and the recorder of the observer's star chart." But it would be as valid to hold that a protractor mediates angles between points in a shape and the geometer, or structural knowledge between Pythagoras and the geometer.
Likewise, the soldered mail containers used in the Pacific island guano trade are "transport media" for the letters sealed within them, between ship and shore. But they are only "communications media" if they are inscribed with the address of the recipient and/or the sender.
Our society often confuses the reference for the referent, and the messenger for the message. One is "on the phone" in the sense of projecting one's self- perception into the medium of the telephone system. We tend to look at the speakerphone in a conference call. My frustration with the Internet targets my keyboard and monitor for abuse, more often than my network cable, or my ISP. Property law is better at protecting a box of blank tapes than the plagiarism of a song.
Our messages, which preoccupy us, are increasingly able to transcend modes of communication, each characterized by different media.
We necronauts chronicle the passing of media into disuse. A rigorous distinction of media from the endpoints that necessitate them, and media that they may transmit (or by which they are transmitted) is a central organizing principle of our endeavor.
Matthew Rubenstein (firstname.lastname@example.org)
North American Media Engines