Memex¶

Definition¶

The memex is Vannevar Bush's 1945 specification for a personal record store: a device holding all of one individual's books, records, correspondence and notes, mechanized so that the whole collection can be consulted with speed and flexibility — in his phrase, "an enlarged intimate supplement to his memory" — mixing purchased material with the owner's own entries in a single store, annotatable in place, with several items projected side by side at once.

Explanation¶

Strip away the microfilm and what remains is a set of design commitments about personal knowledge stores, each of which is a live decision today. Capacity is deliberately designed out of the problem: at five thousand pages a day the owner would need centuries to fill the store, so entry should be profligate and the cost of capture, not the cost of holding, is what governs. Consumed and created material share one store — a longhand note or a photograph goes in through the same platen and files next to a purchased book, and marginal comments attach to either — so there is no boundary between one's library and one's notes. Several projection positions run at once, letting one item stay in view while another is called up, which is not a convenience but the precondition for joining two things. And conventional indexed lookup is kept rather than replaced: the owner can still tap a code and get a book, page through it at one, ten or a hundred pages a stroke, and jump to its index, with associative selection layered on top of that rather than substituted for it. Bush's stated aim for the whole arrangement is to let a person reacquire the privilege of forgetting whatever they do not need immediately at hand, with the assurance of finding it again if it proves important. The source is a magazine essay, not an engineering document, and everything mechanical in it — the levers, the photocell dots, the dry photography — is dead; the specification of the store is what eighty years of personal knowledge tools have been re-implementing.

Key Properties¶

Holds everything the owner reads and everything the owner writes, in one undivided store
Capacity is designed out of the problem, so entry should be profligate and capture cost is the real constraint
Direct entry of longhand notes and photographs, with annotation in place on any item
Several simultaneous viewing positions — the precondition for tying two items together
Conventional indexed lookup is retained; associative selection is layered on top of it, not in place of it

Relationships¶

Selection as the bottleneck of the record — is the problem this device was designed against, and dictates its unusual commitments — cheap entry, mixed sources, several items in view
Associative trail — is what Bush calls the essential feature of the memex — without the tying of items together the device is only a fast filing cabinet
Cognitive debt — puts this design's stated aim under empirical pressure — Bush argued that offloading retention lets a person forget safely, while the cognitive-debt evidence indicates that habitually offloading mental work degrades the engagement it replaced

Applications¶

A specification to check personal knowledge tools against — does capture cost nothing, do notes and sources live together, can two items be held side by side, is indexed lookup still available; and the reference point for arguing that a knowledge store should be private, complete and owner-annotated rather than a curated subset.

Sources¶

https://www.theatlantic.com/magazine/archive/1945/07/as-we-may-think/303881/