Internet. A very naïve analyst will compute (579*100)/1021
and report that 56.71 per cent of respondents have tried Web
surfing. But in a national sample survey of this minimal size
the standard error in sampling the population will often be
or3 per cent. So reporting the surfing number as 57 per
cent of respondents would be reasonable, but would mean only
that there was a 95 per cent probability that the actual rate of
surfing in the whole population sampled was between 54 and
60 per cent. Someone writing 56.71 per cent into their text is
not being any more scientific. Instead they simply reveal that
they have not the least idea of the accuracy level of the basic
data which they are handling.
The ‘need to know’ criterion can also help in determining
whatkindsof attention points are needed or are most appropri-
ate at different points. A simple and unobtrusive way to drasti-
cally cut the complexity of numerical data for readers is to
picture them in charts and graphs instead of providing them in
tables. In an appropriately scaled chart showing how the num-
ber of unemployed people has moved over time, an original
data figure of 1,215,689 may effectively show up for readers as
‘somewhat more than a million’. If that is an appropriate level
of information for readers to have then you can deliver a lot
more data much more accessibly by using a chart. A picture
here can certainly be worth more than 1000 numbers in the
cells of a table.
Somewhat less obviously, the ‘need to know’ criterion can
also help you choose between giving a text-only explanation of
a theoretical argument or condensing some of the conceptual
relationships involved into a diagram. Using a diagram lets you
exploit the two-dimensional space of the page to locate multi-
ple concepts against each other. And employing a recognized
set of diagrammatic conventions (such as the square boxes,
circles and arrows in flow charts) can let you capture different
relationships very synoptically. If you are describing a complex
pattern of causation or interaction then offering readers a
diagrammatic view will help make things clearer and more
accessible for most people. However, remember that some read-
ers may tend to skip diagrams, so always provide an intuitive
text explanation as well. Where the concepts involved are fewer
and the relationships between them are simpler, diagrams may
162 ◆AUTHORING A PHD