Information Technology Reference
In-Depth Information
Chapter 9
Understandability and Usability of Data
I hear and I forget. I see and I remember. I do and I understand.
(
Confucius
)
Ensuring that digitally encoded information remains usable and understandable over
time is, together with authenticity, at the heart of digital preservation. The previous
chapter discussed some of the formal aspects of intelligibility. This chapter discusses
the complementary issue of usability of the data.
Usable means “
capable of use
” (OED), “
available or convenient
for use
”
(
www.dictionary.com
).
In design, usability is the study of the ease with which people can employ a
particular tool or other human-made object in order to achieve a particular goal. In
human - computer interaction and computer science, usability studies the elegance
and clarity with which the interaction with a computer program or a web site is
designed (Wikipedia).
Here, by usable we mean that someone is able to do something sensible with the
information it contains. We recognise that this might not be easy - but at least it
should be possible to carry out.
One could of course use a digital object simply by printing out its constituent
sequences of “1”'s and “0”'s on paper and using this to decorate one's home.
However it seems reasonable to suppose that this has little to do with the infor-
mation content in the digital object - unless of course that is what it was designed
for. For example the Arecibo message [
130
] was designed to be understood by extra-
terrestrials. This consisted of a sequence of 1,679 bits, which if displayed as 73 rows
by 23 columns looks like Fig.
9.1
(the shading has been added on the right to make
the different parts of the image clearer).
The idea is that even with no shared cultural or linguistic roots one can rely on
basic counting, an awareness of prime numbers, elements, chemistry and physics -
which any being able to receive the message might reasonably be expected to
possess.
It is not clear how many human recipients could decipher the message without
help!
