Organization 93
this knowledge is the primary purpose of your thesis. This path, or chain of reason-
ing, is the argument.
In the context of your method, the main thing is that you need to be confident in
at least a preliminary way that the path exists. That is, you need to satisfy yourself
that if you gather certain data, and it has certain desirable properties, then you can
use it to present an argument that your hypothesis probably holds; or that, if the
properties are absent, then the hypothesis is probably wrong.
To continue the earlier example, it might be that your hypothesis is that complex
modelling can reduce vegetable wastage, and applying your model shows that it can
reduce wastage on a certain scenario by 15 %. The argument first needs to persuade
the reader that 15 % is a meaningful reduction: is this a significant percentage of the
total volume of shipped vegetables? What are the costs incurred in the reduction?
And so on. If you are being intellectually honest, you may have, early in your re-
search, considered the question of thresholds; for example, perhaps no case can be
made for the benefit of a mere 3 % gain, while a 10 % gain is unarguably significant,
and so 15 % is a clear success for your model.
The argument should not stop here, because so far it is rather inward-looking,
with results that show that the research is valid in its own terms, but only weak evi-
dence that it has external value. To take the argument further, you might then con-
sider the issue of generalization to other scenarios, and also even consider broader
factors, such as demonstrating that the data that the model needs can be gathered in
practical settings.
A perspective on a thesis is that it is a presentation of an argument largely made
in the results and analysis chapters, but its foundations are laid here, in the chapter
on your contribution. At this point you need to have established for yourself what
the lines of the argument are going to be, and have addressed likely sceptical con-
cerns the examiners might have by examining and justifying your assumptions.
A final note on this point, but a significant one, is that ultimately the argument
and your assumptions are subjective. Your final line of defence, in choice of as-
sumptions, method, and so on, is that they are reasonable and consistent. The final
product of your effort is an objective thesis, but it would be dishonest to disguise the
fact that some elements are essentially choices, whether they arise from constraints
(only certain data was available, resources were limited, and so on) or from explicit
decisions (inclusion of energy considerations made the model intractable). At the
same time, you need to be confident that the reasonableness of these choices is obvi-
ous to others. If you and your examiners cannot agree on the basis of your research,
they are unlikely to respect your outcomes.
Organization
So where do these lines of discussion take you in terms of how to organize the cen-
tral chapters of your thesis? As I noted earlier, practice varies a great deal between
disciplines, and you need to read other theses in your area—and of course get advice