The physical properties of high-quality paper make certain
helpful functions possible or easier for users, including the following.
Lightweight so usually easy to carry, hold, and position
Thin so easy to grasp
Flexible, thus convenient to position, bend, and fold
Reflective, able to be illuminated for a wide range of
brightness and contrast
Markable by a variety of means in a simple and uniform manner
Allowing detailed high-resolution markings
Opaque and two-sided so efficiently legible on both sides
Unpowered so portable and "always-on"
Stable, self-conserving and maintenance-free for many years
Cheap and movable, so many can be used, e.g. spread out side
Simple, easily learned, and widely understood methods of use
Digital display technologies used by today’s digital
libraries (DL's) to deliver document images—a rapidly evolving ecology of
desktop, laptop, and handheld computers, plus eBook readers, tablet PCs, etc—
offer often contrasting affordances:
automatically and rapidly rewritable
Connected (e.g. wirelessly) to a network and so can deliver
potentially unlimited data
Radiant/back-lit, and so legible in the dark, but often
limited in range of brightness and contrast
Sensitive (to, e.g., touch, capacitance), and so markable
This catalogue is incomplete but long enough to suggest the
multiplicity of ways in which information conveyed originally as ink-on-paper
may, and may not, be better delivered by electronic means favored by DL's. One
result is that, as some researchers report, “paper [remains at present] the
medium of choice for reading, even when the most high-tech technologies are to
hand.” They point to four principal reasons for this.
Paper allows “flexible [navigation] through documents”
Paper assists “cross-referencing” of several documents at
Paper invites annotation
Paper allows the “interweaving of reading and writing”
It is illuminating to bear these considerations in mind when
identifying obstacles to the delivery of document images via DL's.
Of course, efforts are underway to commercialize electronic
document displays offering even more of the affordances of paper including
flexibility, low weight, low power, and low cost.