users according to some assumed standard cost- and utility-functions. 
Determine for each group of consumers and each group of instruments 
an experimental design (number of points and location of them), calcula- 
tion rules!4) and suggestions for decision for different outcomes of the 
calculations. This has to be published not only for routine tests, but also 
for delivery control tests of instruments. The basis for reaching this goal 
will be futher theoretical research according the mentioned principles 
and futher investigations of the practical population of errors of the 
existing instruments. 
In this paper the decision problem has been regarded as a game against 
nature. The instrument tested has been assumed (for example in deter- 
mination of the curve in figure 1) as a random sample out of the produ- 
cers population of instruments. The theory of decision will be more 
interesting, if it is assumed that the seller chooses the instrument 
according to his thoughts about the buyer's abilities to test and way of 
testing. This means that more pure game theory has to be applied and 
the decision maker will choose an action strategy according to the rules 
of, for example, a two-person-non-zero-sum-game.15) 
References: 
[1]. Berg, H.: On Quality Control in Survey Technique. (In Swedish). Svensk 
Lantmáteritidskrift 1966: 1. P. 135—147. 
[2]. Burkhardt, R.: Standard Tests for Photogrammetric Plotters. International 
Society of Photogrammetry, II: 2. Frankfurt a. M. 1967. 
[3]. Hald, A.: Statistical Theory with Engineering Applications. New York 1955. 
(Especially Capter 14.) 
14) Of course it may pay to computerize all the described calculations in the 
decision procedure. In that way — for an input of cost functions and probability 
distribution functions and decision criterion — the computer automatically will 
give the optimum number of points and the critical value of the result. (For the 
case of normal distributions and linear costs, the EVSI is tabulated in for example 
[5]. These tables are very useful for practical decision problems.) The graphical 
method of presentation in this paper is thought as pedagogic in order to communi- 
cate the message of the paper to the reader. 
15) It could be observed that the entire decision procedure above is seen only 
in the buyers point of wiev. It is thus, for example, assumed that the deci- 
sion procedure is stated in the buying contract. Otherwise there will exist risks 
for expensive conflicts between the buyer and the seller, when the seller can not 
accept that the decision is based on the calculated critical value. 
158