Information Technology Reference
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then not have to revaluate it. Thus reckoning about what is possible it central in court
case, but the rules, norms and habits that are pertinent in this context serve to limit
what kinds of possibility there are at each stage and to ensure that possibilities are
increasingly constrained as one approaches the verdict.
To sum up, there may be some quite complex reasoning about scope by subjects,
especially when encountering new contexts or when something fundamentally
surprising has occurred, but that between these events scope may be quite stable and
is something that can be elicited.
4
Narrative Elements
Once context and scope have been established, this leaves the everyday kind of
reasoning that people use to reason about action. As Simon observed [16] within very
regular and constrained environments (office situations) the reasoning of people is
better characterised as 'procedural' rather than approximating any kind of ideal (what
he called 'substantive') rationality. That is they have a set of interconnected but fairly
simple set of rules that they use if circumstances are as they expected them to be.
This was also a lesson from the field of “Expert Systems” which attempted to
elucidate rules for how domain experts behaved. The rules they discovered where
surprisingly simple but, of course, this was only within a settled kind of situation with
fairly constrained goals. In a similar vein Giegernezer [8] has identified a host of
fairly simple heuristics that are effective in our daily lives.
The simplest and most common structure for expressing these procedural rules is a
simple conditional: “if
this
(some condition) then
this
(some consequence, action or
calculation)”. Such conditionals can either be used to represent a decision point by
the agent or local causation within the situation. However there are others that are
maybe so obvious that one tends to overlook them, such as: sequencing (“
this
follows
that
”, or conjunction (“
this
… together with
this
”), alternatives (“
this
or else
that
”), or
simple expectations about the situation (“
this
” or “not
that
”). Such local rules form a
kind of logic
1
, which together determine what a person might do, although on the
whole these are not manipulated in very complex ways (except if a revaluation of
possibilities are required, for example in debugging code). Rather than to rely on
complex reasoning, humans often seem to prefer other tactics such as habit, imitation,
or trial and error learning. For example, when faced with 1000s of food choices in a
supermarket we do not make extensive price-utility comparisons, but constrain our
own choices via habit and use alternatives to comparison such as social imitation.
Only in very limited situations (e.g. we have decided to buy baked beans and now
wish to work out which has less sugar in them) do we resort to detailed comparison.
The best (alternatively most natural) way of representing these narrative elements
is not entirely clear. Maybe the argumentation framework of Toulmin [19] would be
helpful here, or maybe we need more of a narrative structure such as that of Able [1].
1
These are not a formal logic but rather an expression of common sense relationships and
beliefs. However the fact that these elements are situated within context and scope makes
them easier to relate to a more formal representation to program the behavior of an agent.
