Särtryck ur Svensk Lantmäteritidskrift nr 2 1968. 
Optimal Testing 
Decision Criteria for Acceptance of a Measurement Instrument 
Harald Berg 
Abstract 
Application of decision theory to photogrammetric calibration problems. 
Optimising of test procedure, i. e. best testing design and rules for the 
best decision according to defined criterions. 
Scope 
This paper is written as a contribution to the coming discussions about 
Standard Tests at the ISP Congress in Lausanne, with the thought that 
it may be considered as a basic philosophy for future work of the work: 
ing group dealing with "Standard tests of photogrammetric instruments" 
of Commission II. It is also the desire of the author to introduce existing 
decision theory into the field of survey technique!), as this theory seems 
to have possibilities of being useful in fields, other than that of instru- 
ment testing. 
The problem 
The task of control measurements is to serve as the basis for a deci- 
sion. We want to base our decision to accept or reject the metric accuracy 
of a photogrammetric instrument on a limited number of indirect deter- 
minations of the standard error, this being an estimate of a figure which 
represents the population of true errors of the instrument. 
As the the errors determined comprise only a sample out of a popula- 
tion of errors, there exists a risk for a wrong decision. Our problem is to 
find a good rule for when to accept and when to reject?). 
All the errors of measurement that will occur during the lifetime of the 
instrument comprises the ideal population of errors. This is practically 
1) The advantages of modern decision theory seem not yet to be taken into full 
consideration by the older decision making generation today — probably due to 
the late development of this theory and thus lacking knowlege. 
2) That is: although we never can know the true status of the instrument, we 
must make the decision. 
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