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STANDARDIZATION OF EXPRESSIONS FOR ACCURACY, DISCUSSION
Discussion
Professeur F. VANDERHEYDEN: Je remercie
Monsieur Hallert pour le résumé qu'il vient de
nous donner de son papier trés important que
vous avez pu trouver, sinon pas lire, dans
,,Photogrammetria". Je considére que ce rapport
dans Photogrammetria est un peu chapitre d'un
cours d'université de la théorie des erreurs et
de l'étude de la précision. Aussi pour ce point
nous remercions Monsieur Hallert d'avoir rédigé
ce rapport.
A- la différence de ce que Monsieur
Schermerhorn avait en vue, notamment de faire
une proposition sans l'espoir qu'elle soit adop-
tee, Monsieur Hallert veut aller plus loin. Il
voudrait que sa proposition serve de base pour
une classification des terms, une terminologie
qui soit acceptée. Il est évident que nous ne
pouvons pas ici décider si oui ou non cette pro-
position qu’il fait dans son rapport est accep-
table ou non, et si nous sommes tous d’accord
pour dorénavant la suivre. Je suis même sûr
que dans la salle il y a des personnes présentes,
je regarde Monsieur Baetslé, qui déjà dès main-
tenant ne sont pas d'accord. Mais la question
que je me pose est la suivante: Est-ce que nous
ne ferions pas bien d'accepter la proposition
faite en final par Monsieur Hallert de désigner
quelques personnes qui voudraient bien se
réunir ou bien s'écrire en vue d'arriver à une
entente. Je suis sür que Monsieur Hallert a dans
la téte quelques noms qu'il pourrait proposer
pour ce groupe de travail, mais je voudrais
d'abord savoir si la salle me suit dans cette
proposition.
Prof W. SCHERMERHORN: I should like to say
a few words because there is some misunder-
standing about what I have said. The intention
was not that it would not be adopted. I am afraid
that if we adopt it, it will have very limited
consequense in use. I think our proposal is the
same as that of Mr Hallert. It is very nice to
introduce definitions. However, I would draw
attention to the fact that more important than
standardisation in this respect is the fact that we
should have a set of clear-cut definitions in
different languages, so that we can derive the
exact meaning from these when a certain ex-
pression is used. That is important. I believe
that all efforts to press theories into the same
frame will fail. Our job is to get definitions in
different languages and compare them. That is
necessary. Such a joint commission, whatever
they have in mind, either the one or the other,
should aim for the best result being of the ut-
most importance. All this kind of work is very
difficult and takes a long time. If you try to get
everybody in the same position and standardise
more or less, then I am sure that nothing will
come out. The only important thing is that we
understand each other’s language. That is im-
portant and it is something which is missing in
photogrammetry, as Mr Hallert has said. I fully
support him.
Prof F. VANDERHEYDEN: Do I understand
that you are against the commission?
Prof W. SCHERMERHORN: No, but I want to
tell the audience that there are two different
lines of thinking in this respect, and that we must
carefully consider which kind of task such a
joint commission will receive: whether it will be
an effort to give a definition in the various
languages as to the meaning of the words or
whether we must all try to talk the same
language. I do not consider the latter possible
when we are dealing with such theoretical prob-
lems. I think we should start by knowing what
we are talking about; that is already difficult
enough. I propose that this should be the first
task of such a joint commission and then we
could look at it again after that.
Mr B. HALLERT: I agree with Professor
Schermerhorn, and I am very grateful to him for
supporting what we have been talking about
here.
It could be mentioned that there are about
fifteen or sixteen different expressions for accu-
racy in use today. I have listed them here but I
have not time to read them. You have the ex-
pressions “the accuracy of", "the precision of"
and "the uncertainty of" which contain all these
fifteen expressions. That is something we could
start with. My proposal is that we should have
a joint commission between Union Géodésique,
the ISP and the FIG which I proposed in
Delft in 1958. I think we could give the new
President of Commission II the task of getting
into contact with the other organisations. I
believe our own Society should create a group
which, in my opinion, should consist of the
following names — and it is important here that
we get the different languages represented —
Professor Bachmann in Switzerland for the
German and for the French; Dr Schmid in the
United States for the German and for the
English; and Professor Roelofs in Holland for
the Dutch. I do not know whether you would
agree to this; it is up to you.
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