102 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 2§
so, because it might be that the return on disaggregation after a
certain point ceases to be worthwhile.
My second comment has to do with the proposal towards agreeing
on a terminology in which to discuss model construction. I have
misgivings about that proposal. Scientific terminology generally
comes about by a process very much like consumer’s choice in the
market place; some authors use new terms that are picked up; the
same authors may have used other terms that were not taken up.
There is a social process of accumulation of terminology that is an
extremely valuable screening process, not only of terms, but also of
the ideas associated with these terms. If we make a concerted effort
‘0 set up a terminology, we may find ourselves unwittingly and
unwillingly setting up ideas rather than terms, because some terms
are most suitable as vehicles for certain ideas. I would therefore put
in a plea for allowing the natural selection of terminology to take
its course also in this area.
VIAHALANOBIS
I should apologise for having failed to convey what I meant by
:erminology. Sometimes we speak of « macro » and « micro » mo-
dels. My point was that it would be useful to have, for example,
an agreed terminology of using the two concepts « macro » and
« micro » in relation to the particular domain of interest of which
we are making a model. Now if we simply wait for general agreement,
such agreement may never be reached. I may give a specific
instance; in social accounts, in national income, it became necessary
continually to have a standard terminology; for example, what should
be meant by « net national income ». I suggested that model making
has now reached a stage where an agreed terminology, in a purely
scientific sense, would be extremely useful for purposes of description.
[ think it is possible up to a point to have a terminology without
Injecting any views in it. ... I may give a specific example. In
my own country, we have distinguished between « projection » and
« target ». « Projection » is what we get from historical experience,
11 Stone - pag. 100