bluuebunny/crossref_metadata_2025 huggingface dataset:
Toets voor de gelijkheid van twee kleine kansen met behulp van even grote steekproeven en net onderscheidingsvermogen van deze toets1
Authors: Klerk‐Grobben Gerda , Prins H. J.
Published: April 2008

A test for comparing two small unknown probabilities, using samples of equal size, and its power.

For testing the difference between two small proportions a slightly revised form of the sign test is used, giving a better approximation of the significance level α and a larger power.

A table of critical values of the test and graphs of its powerfunction are given.
Ordered variables in discontinuous distributions*
Authors: Abdel‐Aty S. H.
Published: April 2008

Samenvatting

Gerangschikte variabelen in discrete verdelingen

Dit artikel behandelt de berekening van de waarschijnlijkheidsverdeling van de y‐de waarneming naar volgorde van grootte uit een steekproef van k waarnemingen van een discrete verdeling, d.w.z. van een stochastische grootheid, die n verschillende waarden kan aannemen. Rekening houdend met de kans op gelijke waarnemingen wordt de exacte waarschijnlijkheidsverdeling van de r‐de waarneming afgeleid voor kleine waarden van k en n. In het bijzonder worden de gevallen r= 1 en r=k beschouwd, terwijl ook de simultane verdeling van de r‐de en de s‐de waarneming naar grootte berekend wordt. De correlatie tussen de f‐de en de s‐de waarneming en de waarschijnlijkheidsverdeling van de “range” warden eveneens beschouwd.

De resultaten van deze onderzoekingen warden toegepast op de binomials verdeling en, met een uitbreiding tot het geval n→∞, op de verdeling van Poisson. Voor deze twee gevallen geeft de schrijver benaderingen voor de momenten van de onderzochte waarschijnlijkheidsverdeling, die in het geval van de binomiale verdeling alleen gelden voor niet te kleine n.
Statistische analyse van muziek
Authors: Lisman J. H. C.
Published: April 2008

This paper presents an application of statistical methods in analysing music. By counting the notes in pieces of music, frequency distributions are obtained and analysed.

Particularly Bach's compositions are considered, which appear to be rather disciplined as to the use of the 12 notes in dependence of the key. Perhaps it would be possible to characterize different composers by means of these frequency distributions.

Also a specimen of modern music without any key is discussed.
Confidence intervals associated with a straight line fitted by least squares
Authors: Kerrich J. E.
Published: April 2008

Een betrouw baarheidsstrook voor een rechte lijn, bepaald met behulp van kleinste kwadraten.

In de regressie‐analyse kan men op vrij eenvoudige wijze een betrouwbaarheidsinterval vinden voor één punt van de regressielijn, behorende bij een willekeurig gegeven waarde van de abscis. Dit onderwerp wordt in de meeste handboeken over statistiek behandeld. In tegenstelling hiermee wordt een andere vraag, die hier nauw rnee samenhangt, meestal niet behandeld. Dit is het bepalen van een betrouwbaarheidsstrook voor de lijn in zijn geheel. In dit artikel worden beide methoden besproken.
“Design and analysis of industrial experiments”*
Authors: Davies O. L. , En F. J. van Dun , Hamaker H. C.
Published: April 2008

Design and analysis of industrial experiments

This paper is based on a lecture on the “Design and Analysis of Industrial Experiments” given by Dr O. L. Davies on the 8th of May 1954 to the Industrial Section of the “Vereniging voor Statistiek”. Production, formulation, and testing are distinguished as three separate fields of chemical activity where experimental designs can be applied, and various numerical examples of such experiments are discussed in detail. They consist of a 23factorial design, a 24half replicate and a 25quarter replicate fractional factorial design, and a three‐way classification. In a final section the recent designs developed by Box for the exploration of response surfaces are briefly considered.
Toespraak door de directeur van de Stichting “Kwaliteitsdienst voor de Industrie”
Authors: de Fremery J. D. N.
Published: April 2008

Adress of the Director of the Foundation Industrial Quality Service.

The increasing of productivity also has an important qualitative aspect, To promote the qualitative increase of productivity the “Kwaliteitsdienst voor de Industrie” (Industrial Quality Service) wants to organize courses through which the statistical quality control methods can for each separate branch of industry be made available to those who are able to apply these methods, but who cannot spare the time and the energy required to take fully note of the mathematical and statistical backgrounds.
Belletjes in glasbuizen – de keuze van de fabricagemethode van een massaproduct *
Authors: Seligmann P. S.
Published: April 2008

For a certain mass production pieces of glass tubing are required, 6 cm long, free of bubbles and coated inside with an expensive coating. These pieces are obtained by cutting away the bubbles from tubes 100 cm long, coating the remaining pieces with a minimum length of 33 cm and finally cutting the coated pieces of tubing into pieces of 6 cm.

A discussion is given about the relations between the costs of production and various technical parameters, and about the conditions necessary for minimizing these costs.
Schema's ter oplossing van lineaire programmeringsproblemen *
Authors: Kriens J.
Published: April 2008

Schemes for the solution of problems in linear programming.

Expository paper about the application of the simplex method in linear programming. The method of solution is given in the form of a number of tables and computational diagrams. No proofs are given; a list of references is included.
Bepaling van het optimale controle‐interval*
Authors: Wijvekate M. L.
Published: April 2008

This paper deals with control techniques in automatic industrial processes. By means of a simplified model a method is developed to determine the optimum control interval.

The results are applied to a chemical process, to quality control and to multi‐machine‐operating.
Militaire toepassingen van Operations Research*
Authors: Zoutendijk G.
Published: April 2008

Military applications of Operations Research.

Modern warfare is so complex that military commanders cannot be expected to survey all the features of a military operation or a new armanientsystem. They need scientists to assist them in taking decisions.

Operations Research was of great importance in World War II. It is concerned with the study of weapons, tactics and strategy. In this paper some of the results of O.R. are treated. After the war O.R. scientists have continued their studies. The Korean war has supplied new experimental data. The methods of O.R. have become of great importance in industry too.

A little country like Holland is dependent on her bigger allies as to many results of O.R. Nevertheless there are fields where scientific research bf the Dutch is required. The territorial defence is one of them, because of the special difficulties presented by the Dutch territory: the existence of land below sea‐level, where heavy tanks cannot operate, and where it is impossible to dig foxholes; the A. A. defence of dikes, and the consequences of the bursting of a dike. O.R. can help to solve the difficulties.
Enige opmerkingen over de berekening van de verwachting en de spreiding van het aantal inconsistenties in een bepaald rangcorrelatieschema*
Authors: Kesten H. , Runnenburg J. Th.
Published: April 2008

Cf. summary of the preceding paper by Ph. van Elteren and W. F. van Peype.
Statistical priesthood *) (Savage on personal probabilities [1])
Authors: van Dantzig D.
Published: April 2008

Samenvatting

In verband met de huidige ontwikkeling van de ekonomische beslissingstheorie heeft de subjectivistische opvatting van net waarschijnlijkheidsbegrip tegenwoordig weer meer aanhangers dan enige tijd geleden. Eén daarvan is Leonard J. Savage, die deze opvatting in zijn boek “The foundations of statistics” [1] nadrukkelijk verdedigt. Daarom wordt in dit artikel het boek van Savage en de subjectivistische opvatting in het algemeen aan een kritisch onderzoek onderworpen. Ter vergelijking worden de opvattingen van Jacob Bernoulli, en ook die van de schrijver van dit artikel, kort samengevat. Het boek bevat vele en ernstige gebreken. Noch zijn beschouwingen, noch zijn voorbeelden wettigen het vermoeden dat schrijver veel statistische ervaring bezit.

Voorts wordt uitvoerig aangetoond, dat het “beginsel van de kleinste spijt” op niet ter zake doende gronden kan leiden tot strategieën die verre van optimaal zijn en altijd bijna het slechtst mogelijke resultaat hebben. Dit van Savage afkomstige beginsel mag daarmede wel als definitief weerlegd worden beschouwd.
Statistiek en Marktanalyse: Inleiding tot de Statistische Dag 1957
Authors: Kohnstamm G. A.
Published: April 2008

It is only seldom that one can collect sufficient statistical data to effect concrete market researches asked for. Therefore the main problem for the market analyst is on the one hand how to obtain, with reasonable efforts, the figures he needs, and on the other hand, how to arrange them in such a manner that it is possible to deduce from them conclusions that form reliable “tools for management”. After a preliminary speech to introduce the subject of the “Statistische Dag”, the author treats some market‐research problems with which a Netherlands exporter of raw materials for the textile industry has to contend.
Substituut‐variabelen in correlatieberekingen
Authors: Somermeiier W. H.
Published: April 2008

The recently repeated assertion that in correlation analysis it makes little difference whether one variable (x2) is used instead of another one (x3), provided the coefficient of correlation (r23) between x2 and x3 is high, is scrutinized.

To that purpose the ranges of coefficients of correlation with respect to the substitute variable are expressed in formula 3. Moreover, by way of example, extreme values of coefficients of simple correlation (r13 and r34), of multiple correlation (R1.34 and R3.14) and of regression (α13 and α14, α31 and α34) relating to the substitute variable, are calculated on the basis of empirical values of coefficients of simple correlation relating to the substituted and the remaining variables.

The outcome of those calculations are summarized in the tables 1 and 3, and in the graph.

Table 1 presents ranges of r13 for given values of r12 and r23, table 3 shows extreme values of coefficients of single and multiple correlation and regression in case an additional variable x4 is introduced and r12, r14, r24 and r23 are given. The graph shows an ellipse as the boundary of the inner closed domain of compatible values of r13 and r34.

Those results clearly indicate the need for caution in substituting one variable by another.
Statistical Priesthood II: Sir Ronald on Scientific Inference*
Authors: van Dantzig D.
Published: April 2008

Partly as a critical review of Sir Ronald Fisher's latest book, partly as an essay, Fisher's theory of likelihood and fiducial inference is carefully considered. As to the latter, it is found that in the form presented it contains errors, but that an interpretation is possible which seems to be in agreement with Fisher's views and which admits of a mathematically correct treatment. This necessitates a clear distinction, also formally, between random variables and numbers. The definition given here of random variables possessing Fisher's fiducial distributions might perhaps provide a common platform on which adherents and opponents of Fisher's view could meet and maybe understand each other. Part of the method and its results can also be justified, and in this light fiducial inference appears as an elimination method for unknown parameters. As such it has indubitable merits, but a rather limited domain of applicability. In these cases the same results can also be obtained by other methods, in particular the theory of confidence domains. In other applications, however, not covered by the Neyman ‐ Pearson theory, in particular in the Behrens‐Fisher test, the confusion between random and constant quantities has caused irreparable errors. Notwithstanding a strenuous and prolonged effort to interpret Fisher's often obscure statements in agreement with his philosophical ideas, no justification for these applications could be found. Since the criticism by previous authors remains valid, or comes back in other places, there can no longer be any doubt that these applications are erroneous1).
Voetbalprognoses
Authors: Jochems D. B.
Published: April 2008

Football pools

A main point in the discussions of whether the Dutch football pools are in defiance of the law is the problem of skill in prediction. It is said that experts on football have a greater chance to win prices in the pool than other participants and in this respect the pool differs from a lottery. The author makes an analysis of the scores of the prognoses of football journalists, under the assumption that these journalists are experts in predicting the results of football matches. He finds that journalists, if participating, would never have won a price in a pool and that mechanically applied non‐expert methods of forecasting yield predictions which are not much worse than the scores of the supposed experts.
Opleiding en intelligentie volgens de legerkeuringen *
Authors: Sandee J. , Ruiter R.
Published: April 2008

Education and intelligence according to tests of conscripts.

All Netherlands conscripts are subjected to five psychological tests. The test results for a sample of approx. 2000 conscripts have been split up according to school education received, and first and second moments were calculated.

While different levels of education are accompanied by significantly different average test results, the variance within each group is still very large.

Principal component analysis indicated a preponderant “general level” factor and a small “technical bias” factor. No single school type produces boys of modest “general level” but good “technical bias”.
Bepaling van stuwende en verzorgende bedrijfstakken door middel van statistische methoden
Authors: Venekamp P. E.
Published: April 2008

Determination of basic and non‐basic enterprises by means of statistical methods.

In this article a sketch is given of the various methods used to obtain a clear insight into the meaning of the non‐basic enterprises and the enterprises which because of their basic character belong to the factors determining the development of the population. Special attention has been paid to the method which puts the whole problem of the definition of basic and non‐basic industries in the framework of a system of equations. This system has been built up from regional social accounts that have been developed for Amsterdam.
De bloedproef statistisch bezien
Authors: Rumke L. , Bloemena A. R.
Published: April 2008

Statistical aspects of the Widmark procedure for determining alcohol.

From data given in the literature the standard deviation of the alcohol content of the blood of persons involved in accidents and suspected of being under the influence of alcohol is evaluated. This standard deviation has been found to depend on the number of samples used, on the number of analysts involved in the procedure, on the time interval between the accident and the sampling of the blood and on the standard deviation of the factor β (the decrease of the alcohol content of the blood during one hour without additional consumption of alcohol).
Proeve ener nieuwe personeelsterkte‐grafiek
Authors: Sliggers B. C.
Published: April 2008

A new graph to represent the number of employees, including the periodical variations.
Statistische proefopzetten: bewijs en detectie*
Authors: Hemelrijk J.
Published: April 2008

Statistics: proof and detection

The validity of the conclusions drawn from a statistical analysis depends to a great extent on its historical development. If the experiment has been designed carefully in order to find the answer to questions specified in advance by means of experimental and statistical methods agreed upon before the observations are available, the validity of the conclusions is only restricted by the level(s) of significance used. If, on the other hand, the observations have given rise to new questions, which are then investigated on the basis of these observations themselves or if, during the analysis the statistical methods are changed in order to adap them to the observations, the validity of the conclusions may be impaired. In statistical practice the latter situation seems to be the rule and the former the exception; mixtures of both also occur very often.

In this paper the importance of distinguishing between these two methods of using statistics is stressed. Whereas in the first case one might speak of a “statistical pro of”, the second method — however useful it may be — has the character of “statistical detection” and should strictly speaking always be followed by a corroborative experiment which meets the conditions of a statistical proof. When writing a statistical report one should provide the reader with sufficient historical data to enable him to judge the validity of the results for himself.
Roteerbare proefopzetten*
Authors: Bloemena A. R.
Published: April 2008

Rotatable designs

An expository paper on the rotatable designs developed by Box and Hunter, and their use in regression analysis.
Het experimenteel bepalen van optimale condities*
Authors: Leppink G. J.
Published: April 2008

Experimental determination of optimum conditions.

This article deals with the problem of determining by experiment conditions giving an optimum result. The following is an exposition of a method discussed by Box.
Toepassing van statistiek bij experimenter! in een farmacologisch laboratorium*
Authors: Rumke L
Published: April 2008

The application of statistical methods on experiments in a pharmacological laboratory.

Statistical analysis of various laboratory data demonstrated: (1) the necessity of the application of randomisation procedures in experiments in which mice or rats of different weights are used, (2) the fact that the technical aspects of a chemical determination can be of importance for the experimental design, (3) a case of spurious correlation.
Statistiek en experiment rondom het poliomyelitis vaccin*
Authors: van Strik R.
Published: April 2008

Statistics and experiment about the poliomyelitis vaccine

Adequate controls to ensure unbiased conclusions form an essential part of clinical experiments.

The field trials of S a I k's poliomyelitis vaccine carried out in the U.S. in 1954 are discussed as an example of the need for such controls and the errors that may be introduced when they are omitted or incorrectly devised.
Een geval van statistische detectie*
Authors: Hemelrijk J. , van Herk C. G. G.
Published: April 2008

A case study of statistical detection

In a medical investigation the data proved to be of insufficient accuracy to arrive at definite conclusions. No control observations were available to estimate the accuracy. However, speculations of a reasonable character aiming at the elimination of the least accurate observations led to a clear issue. This may serve as an example of the use of statistics as a mean of detection, to be followed eventually by a well designed new experiment for proof.
De recente ontwikkeling in proefopzetten met kwantitatieve facto ren*
Authors: Hamaker H. C.
Published: April 2008

Recent developments in experimental designs for dealing with quantitative factors.

This paper reviews some recent developments in experimental designs for dealing with quantitative factors.

Successively discussed are:

Rotatable designs (Box),

Evolutionary operation (Box),

Experiments with mixtures (Scheffe),

Experiments with 10 to 100 factors (Satterthwaite),

Random vector experiments,

The use of electronic computers in fitting non‐linear models,

Research Strategy (McArthur).
Design for decision in het clinische experiment*
Authors: de Jongh D. K.
Published: April 2008

Design for decision in the clinical trial.

Whereas an engineer would refuse to undertake the construction of an impossible bridge, the doctor is often compelled to act without a sufficient theoretical basis. Although it is common practice to describe this type of activity as the art of medicine, it should never be forgotten that this so‐called art is not a desirable state but a deplorable necessity. The ideal is medical activity derived entirely from scientific knowledge. It is the object of scientific medicine to reduce the necessity of using „impressions” as premises in medical reasoning. The only valid type of reasoning in medicine is the statistical reasoning. The nature of statistical reasoning is described in non‐technical language.

The author stresses the extreme difficulty of obtaining certain knowledge in the field of therapy. The main reasons for this are (1) the variability of the material, which is irreducible, because no two individuals are exactly alike, (2) the uncertainty of our knowledge, which prevents us from exactly defining classes, (3) the placebo effect of any medical intervention, and (4) the limitation of experimentation by ethical considerations. These difficulties are analyzed and illustrated with examples. The development and limitations of modern medical statistical methods are described.
Een steekproef ter vaststelling van de verdeling van de hoenderstapel
Authors: Vos J. W. E.
Published: April 2008

A sample estimate of the poultry distribution

In 1954 a sample survey was carried out of the returns of the agricultural census, May 1954, in order to establish the distribution of the number of holdings and the number of poultry, by size‐group of arable land and by size‐group of number of poultry. A simple 10 per cent, sample was planned and the expected variances of the numbers of poultry in each size‐group were estimated beforehand. The method of estimation is indicated in this paper. This resulted in comparatively high relative errors in the size‐groups above 500 hens and also in the size‐groups of arable land. Therefore holdings with 500 hens and over were enumerated completely. Some tests were performed with the sample results and finally the efficiency of the stratification is discussed.
Produktiviteit en statistiek
Authors: van Ettinger J.
Published: April 2008

Productivity and Statistics.

Introduction to this special issue concerning productivity and statistics. Theauthor gives a brief general survey.
De statistiek van de Militair Geneeskundige Dienst
Authors: Hoeflake G. J.
Published: April 2008

The author gives a review of the origin and use of the statistical material used in the medical corps of the Dutch army. He points out the value of employing the data in a statistical manner for planning the medical care of the troops.
Verhoging van de arbeidsproduktiviteit in de bosbouw door rationalisatieonderroek
Authors: Bol M. , Gerritsen A. G. , van Soest J.
Published: April 2008

The paper contains a description of field experiments on the use of various implements and of certain working‐methods in the planting of pine forests. The fact that there are two important criteria, i.e. time‐saving and quality of the work, led to a complicated factorial experiment, which was analysed in two different ways, each referring to a part of the data.
Econometrische produktiviteitsanalyses*
Authors: Somermeijer W. H.
Published: April 2008

Some aspects of econometric productivity analysis are discussed. Methods for ascertaining (non‐)optimality of the structure of production, and ways of evaluating the impact of scale of production and of product composition on productivity are indicated by means of examples.
Produktiviteitsverhoging bij accountantscontrole door toepassing van gelaagde steekproeven
Authors: de Wolff P.
Published: April 2008

The auditor's productivity: application of stratified sampling to an auditing problem.

In this paper it is shown that the use of stratified sampling can lead to a considerable saving of costs in auditing operations and thus increases the auditor's productivity.

The sampling method to be described will render it possible to say that the total value of the transactions will not differ more than a fraction ϕ, given in advance, from the correct total value, apart from a probability not surpassing a preassigned level e, on condition that a certain acceptance criterion is fulfilled. Taking into account the auditing costs, the author gives an optimal sampling design and calculates the savings obtained.

Finally the theoretical results are applied to a population of clerical transactions, with an exponential and a logarithmico‐normal distribution respectively.
Optimale hoeveelheid machinegereedschap
Authors: van Hees R. N. , van den Meerendonk H. W.
Published: April 2008

In this article the following problem is discussed: a machine is working continuously, while the shops repairing its tools, work only for a certain time of the week.

The chance of stopping, owing to shortage of tools ready for use, is determined as a function of the total number of tools present. Concluding, the stopping costs of the machine are balanced against the carrying costs of the tools.
Efficiency in de Statistiek*
Authors: Wiggers B. G.
Published: April 2008

Efficiency in Statistics.

A survey is given of the concept efficiency, as used in various sectors of mathematical statistics.

Fisher has been the first to formulate some exact criteria for comparing the efficiency of estimation methods; essentially it is a matter of the number of observations in relation to the precision of the estimate. However, so called quick and dirty estimates, although less efficient according to Fisher, are very useful in practice.

A comparison of distribution‐free and corresponding classic testingmethods is possible with the aid of the concept (local) relative efficiency, as developed by Pitman. It is possible to extend the concept efficiency by the introduction of the element of costs, as shown by various models in the field of social and industrial sampling investigations. However, even then not all efficiency problems have been solved. Finally it is possible to give considerations about efficiency in the case of the design of experiments.

It is clear that efficiency in statistics is possible only to a certain extend and further that efficiency i n statistics in itself is quite a problem.

Efficiency b y statistics depends as well on the right choice of the statistical model, in dependence on numerous influences of the concrete situation.
Een symbool voor I so moor*
Authors: Kuiper N. H.
Published: April 2008

A symbol for Isomorous.

Following D. van Dantzig, we call two random variables or vectors isomorous, if they have the same cumulative distributionfunctions. In this paper we introduce the symbol ≅ (x ≅ y) for this equivalence relation, and we demonstrate that the use of this symbol simplifies the formulation of many statistical problems, statements and theorems.
Wachttijden van patienten*
Authors: Fortuin G. J.
Published: April 2008

Waiting‐times of patients.

In Philips Health Centre all patients were expected to be present at the beginning of the consulting hour. Consequently the waiting‐times of the patients were very long. Usually these patients work normally.

A new system was worked out, whereby the patients appear at the centre with certain intervals. This interval was determined in such a way that the waitingtime of the patients is minimal subject to a waiting‐time which is acceptable for the physician. By that the avarage waiting‐time of the patients was decreased from 44 minutes to 11 minutes per patient.
Onderlinge omzetvergelijking*
Authors: ten Have O.
Published: April 2008

Mutual comparison of turnover.

The owners of industrial enterprises have an inclination to compare their turnover with that of enterprises which work under approximately the same conditions e.g. with regard to locality, assortment and size of the turnover. However, it is very well possible that the trend of the turnover of these approximately similar undertakings diverges from the development of the turnover of the entire line of business. A comparison of enterprises with regard to the development of the turnover will therefore always have to comprise both a comparison with the corresponding group and with the entire line of business.
Efficiency en Economische Statistiek*
Authors: Goudswaard G.
Published: April 2008

Efficiency and Economic Statistics.

Some optimum problems are dealt with in connection with the collection and elaboration of economic statistics; which amount should be made available in total for economic statistics; how this amount should be distributed amongst the various statistics; how the amount made available for a particular statistical project can be used as efficiently as possible.
Efficiency‐onderzoek met behulp van statistische methoden*
Authors: Klaassen L H.
Published: April 2008

Efficiency research by means of statistical methods.

Time studies are an important auxiliary means for the examination of efficiency, but the ordinary regression analysis is often an appropiate instrument to establish working standards with greater accuracy and on a more objective basis. This is illustrated by a few examples.
Normalisatie als beslissingsprobleem*
Authors: Sittig J.
Published: April 2008

Normalisation as a decision problem.

Mass production is the base of the enormous increase of prosperity in the western countries. Normalisation, which means a restriction of the number of types, quality etc. of a certain commodity, is an essential part of this development. However, normalisation has one disadvantage: no account can be taken of the wishes of the individual consumer. Consequently a loss‐function belongs to every imaginable set of types of a given commodity. The set of types must be chosen in such a way that the loss has its minimum value.
Attributenkeuring in theorie en praktijk*
Authors: Hamaker H. C.
Published: April 2008

Theory and practice of sampling by attributes.

This paper brings a survey of present day theory and practice of sampling by attributes. In section 2 the main points in the theory of OC‐curves are recapitulated. Section 3 lists the various features which people have attempted to incorporate in sampling tables, and the various factors which influence our choice of a sampling plan. Subsequent sections discuss economic theories, the importance of the distribution of the precentage of defective items over the inspection lots, the relation between sample size and lot size, and some of the existing sampling tables. In a final section the possibilities for further improvements in existing sampling practices is considered. One conclusion is that in many situations a constant sample size regardless of lot size would have very definite advantages.
Internationale Statistieken*
Authors: Goudswaard G.
Published: April 2008

International statistics.

Report of a lecture by Professor G. Goudswaard on international statistics. The speaker stressed the difficulties of comparing national statistics, as a result of differences in definitions, scope and classification of the statistics, peculiarities of language and structural and legal idiosyncrasies of the countries concerned. He sketched the activities of the international organisations in this field, especially by producing standard classifications for causes of death, international trade, economic activities and occupations. He ended by indicating their limitations.
Stochastische Approximatie*
Authors: Fabius J.
Published: April 2008

In this expository paper attention is drawn to the Rqbbins ‐ Monro approximation procedure for the root of a regression equation and to the modification of this method proposed by H. Kesten.

Both methods are used in a simulated experiment. An outline is given of several related methods.
Inleiding tot de tabelkunde
Authors: Somtrmeljer W. H.
Published: April 2008

Elements of tabellology.

An outline of a system for constructing tables is presented, exemplified by a set of tables for a simple Establishments Census.
De invloed van een prioriteitsregeling op de gemiddelde wachttijd*
Authors: Steutel F. W.
Published: April 2008

The effect of priorities on the average waitingtime.

A waitingtime process is described in terms of customers arriving at a single counter. In the first part of the article the formulae of A. C obham [1] and [2] for the case of two priorities are applied to the following situation: customers arrive in such a way that the interarrival timessare mutually independent and exponentially distributed with mean λ‐1. Servicetimessare mutually independent and independent of the interarrival times. The distributionfunction ofsis indicated by B (s), the mean ofsby μ. The customers are divided in two groups, group 1 consisting of the customers having servicetimes cμ, group 2 of those having servicetimes > cμ, c being a positive number. Servicing takes place as follows: priority is given to customers of group 1 i.e. service of a customer of group 2 starts only if no customers of group 1 are present, customers of the same group are served in the order of their arrival, servicing of a customer is not interrupted.

Keeping λμ < 1 the mean waitingtime εω* for an arbitrary customer is then calculated by means of Cobham's formulae and compared with the mean waitingtime εω, in case that no priorities are given. Under hypothesis of differentiability of B (s>

is the (unique) value of c which minimizes εω*. It is shown that always c*> 1.

In the second part a situation is considered which has been treated by T. E. Phipps [7]. In this situation the customer having the smallest servicetime of all customers present when the counter becomes free is served first. The mean waitingtime εω** in this case is compared with εω and εω*.

Some examples and graphs are given.
Afleiding van kwartaalcijfers uit jaartotalen
Authors: DOORNBOS R. , LISMAN J. H. C.
Published: April 2008

Summary  Quarterly figures may be required when only a sequence of annual totals is available. This article presents two reasonable methods for “interpolating” quarterly figures by means of appropriate minimizing procedures.

The first method relates to minimizing the sum of squared second differences of the quarterly figures, the other one is a linear programming procedure which refers to the absolute second differences. Both methods are illustrated by a numerical example, the first one giving somewhat better results.
Een berekeningsmethode voor de logistische curve
Authors: ERKELENS J.
Published: April 2008

Summary  “Simple estimation of the parameters of the logistic curve.”

By means of an appropriate transformation of the dependent variable Yt into a simple function of Yt, which depends only linearly on time, one of the parameters can be estimated in the usual way. A second transformation leads to the estimation of the two remaining parameters. As a numerical illustration two examples are presented.
Een Monte‐Carlo‐bepaling van overschrijdingskansen, in verband met een keuzetest
Authors: Nass C. A. G.
Published: April 2008

A Monte‐Carlo method for a test of significance, applied to points on a lattice, in connection with a vocational preference test, by C. A. G, Nass.

Appendix by Constance van Eeden.

A periodical rectangular lattice, with a period of k.m, is considered. Thus there are N = k.m points on the lattice, repeated in the two perpendicular directions. Two points are said to be “connected” if they are adjacent in a straight or diagonal way. Thus, if k and m 3, every point is connected with 8 other pooints. Out of the N points of the lattice, n points are selected and the total number of connections x, of all possible pairs of those n points is considered for a vocational preference test with k = m = 9, N = 81, n = 10. The problem is to test whether the sum y = x1+…+ x*** from a sample of h values of x, is significantly small, under the hypothesis that in the h cases the n points are selected at random with equal chance. A Monte‐Carlo sample of 100 values ofxwas taken, using random numbers. For h = 1, the problem was solved by the determination of P(yx1), assuming that y is taken at random from the 101 values of x, supplied by the Monte‐Carlo sample and x1for fixed values of x1. For h ‐ 2, a similar solution is given. For greater values of h, Student's two‐sample test, with correction for continuity is suggested. For h = 2 the results of Student's test are compared with those of the solution mentioned above.

In the appendix a summary is given of results found by P.A.P Moran and P. V. Krishna Iyer for some closely related problems. Further some results concerning exact distributions, moments and asymptotic distributions for C. A. G. Nass' problem are given. The proofs of these results may be found in a paper by C. van Eeden and A. R. Bloemena(1959).
Een mathematisch model voor een reserveringsprobleem
Authors: Kosten L
Published: April 2008

A mathematical model for a booking problem

Air companies have several problems in connection with booking. Clients may book for a certain flight some time in advance and are also allowed to cancel their bookings.

As a result of this it is possible that an airplane leaves with some places empty or that the company, expecting some clients to cancel their booking, has sold to many places.

In both cases losses are the result. In this paper a booking policy that minimizes the expected losses is developed.
Conditional limit‐distributions for the entries in a 2 times 2‐table*
Authors: van Eeden Constance , Runnenburg J. Th.
Published: April 2008

Samenvatting

Voorwaardelijke limietverdelingen voor de stochastische grootheden in een 2X2‐table.

In dit artikel worden de voorwaardelijke limietverdelingen van de stochastische grootheden in een 2X2‐table beschouwd. Tevens wordt aangegeven heo deze limietsellingen gebruikt kunnen worden om overschrijdingskansen bij een 2X2‐table te benaderen.
Een smaak‐onderzoek
Authors: Fortuin G. J. , van Beek A.
Published: April 2008

A comparison has been made between three designs for flavor testing. In the test‐situation even a flavor‐difference which might be noticed by only a few people was of practical importance. In addition not only the unjustified rejection of the null hypothesis (no flavor‐difference), but also the unjustifed rejection of the alternative hypothesis might have important practical consequences.
Achtergronden van planning*
Authors: Hulshof A. H. , Wouterse J. J.
Published: April 2008

Planning as a tool to achieve order from disorder

In many factories the question arises how to obtain the highest degree of occupation of the machines. This problem is often complicated by the fact that the time of flow through is very valuable, not on account of the direct costs as room, interest and risk, but with a view to the possibility to offer a short time of delivery for the products.

This paper deals with the question how the time of flow through can be shortened by creating order in the supply of materials to the relatively expensive and highly occupied machines.
Orde en wanorde in de medische statistiek in ziekenhuizen*
Authors: Scheijde E. H.
Published: April 2008

Order and disorder in medical statistica

In this lecture the author of the publication „Evaluation of medical data from hospitals” dealt with some problems of medical statistics in hospitals.

In the medical sphere there is a lack of interest in medical statistics, because the view‐point of the statistician is so different from the usual view‐point of the clinician. It will be necessary to create a chair in medical logistics in order to increase the knowledge of the physicians on the subject of construction and furnishing of hospitals and consulting‐rooms, of administrative systems, of statistical problems, of efficiency and economics, etc.

The medical and hospital organisations will have to consider the need for a central body for the creation of a uniform medical registration. Research workers need expert help from statisticians in order to be able to draw statistically sound conclusions from their findings; a special organisation might be indispensable to provide this kind of help.

It is hoped that in this way it will be possible to reduce the lack in hospital statistics which is existing in the Netherlands.
Orde—Wanorde—Statistiek*
Authors: ten Have O.
Published: April 2008

Order—Disorder—Statistics

1. Disorder in statistics, which is orderly in virtue of its function, will always occur, since it is the work of men.

2. What statistics are useful depends on the Social‐historical period in which we live. A source of disorder may be the continuance of statistical investigations that belong to former periods.

In our century the available means for socio‐economic statistics should be used in the first place for statistics which are serviceable for systematic planning.

3. Nowadays the importance of statistics for this planning is overestimated. It is not given to man to predict the future with certainty. Also statistics depend on experience, on what is happening empirically. Taking decisions with regard to systematic planning and bearing the risks involved in beyond the scope of the statistician.
Aselect
Authors: Hemelrijk J.
Published: April 2008

Summary

Inaugural address by Professor J. Hemelrijk at the University of Amster‐

Dames en Heren Bestuurders van Amsterdam,

Kievrouw, Mijne Heren Curatoren van de Universiteit van Amsterdam,

Mijne Heren Leden van net Presidium,

Dames en Heren Hoogleraren, Lectoren, Docenten en Leden van de Wetenschappelijke en Administratieve Staf,

Dames en Heren Studenten en voorts Gij alien, die door Uw aanwezigheid van Uw belangstelling blijkt geeft,
A simple derivation of the limiting distribution function of a sample quantile with increasing sample size
Authors: van der Vaart H. R.
Published: April 2008

Samenvatting

De verdeling van een steekproef‐quantiel is, gelijk bekend, asymptotisch normaal. De bewijzen in de meeste bekende leerboeken richten zich op de waarschijnlijkheids‐dichtheid van deze verdeling. Hier wordt een doorzichtig bewijs gegeven, dat uitgaat van de [cumulatieve] verdelingsfunctie en dat aansluit bij de stelling van De Moivre — Laplace over de asymptotische normaliteit van de binomiale verdeling. Het leidt tevens tot eeen suggestie voor betere normalebenaderingen voor de verdeling van een steekproef‐quantiel.
Een algemene inleiding tot de sequente analyse*
Authors: Rümke L
Published: April 2008

A general introduction to sequental analysis.

A general introduction to sequential analysis is given in this paper after recapitulation of the classical theory of testing a hypothesis.
De medisch‐ethische zijde van de sequente analyse*
Authors: Goslings J.
Published: April 2008

The medical‐ethical aspects of sequential analysis in controlled clinical trials.

The ethical problems connected with different methods for assessment of the value of a new therapy are discussed with special reference to the sequential analysis in controlled clinical trials.
Sequential analysis in medicine*
Authors: Armitage P.
Published: April 2008

Samenvatting

Sequente analyse in de Geneeskunde

De analyse van klinische onderzoekingen door toepassing van sequente methoden maakt het mogelijk een onderzoek spoedig te beëindigen indien er een groot verschil blijkt te bestaan tussen de effecten van de te vergelijken behandelingsmethoden. “Afgeknotte” sequente schema's bieden bovendien het voordeel dat aan het noodzakelijke aantal waarnemingen een grens kan worden gesteld. Er worden enkele voorbeelden gegeven van onderzoekingen die volgens een dergelijk schema werden uitgevoerd.
Two restricted sequential sign tests*
Authors: van Elteren Ph.
Published: April 2008

Samenvatting

Twee afgeknotte sequente tekentoetsen.

Sedert enige jaren worden door Dr. P. Armitage sequente methoden gepropageerd, waarbij het aantal benodigde waarnemingen om tot een beslissing te komen beperkt is. Daarnaast bestaan er afgeknotte versies van de klassieke sequente schema's van Wald. Hier wordt een sequente tekentoets volgens Armitage (A) met 3 beslissingsmogelijkheden vergeleken met de overeenkomstige afgeknotte Wald‐toets, welke nader is beschreven door De Boer (B). Aangetoond wordt dat de efficiëntie van toets B groter is dan die van toets A. Daarentegen is toets B sterker afhankelijk van de volgorde waarin de resultaten worden verkregen dan toets A, zodat de laatste in vele gevallen toch verkieslijker zal zijn.
Enige voorbeelden van stochastische processen*
Authors: Runnenburg J. Th.
Published: April 2008

Dames en Heren Bestuurderen van Stad en Universiteit, Dames en Heren Professoren, Lectoren, Privaatdocenten en Leden van de Wetenschappelijke Staf, Assistenten en Studenten en voorts Gij allen, die door Uw tegenwoordigheid van Uw balangstelling blijk geeft.

Zeer gewaardeerde toehoorders.
Aantekeningen bij de herziening van de methodiek der prijsindexcijfers van het levensonderhoud
Authors: van Braam A.
Published: April 2008

Momentarily (fall 196o) the Netherlands Central Bureau of Statistics is revising its price indexnumbers of family living. Some features of this revision are summarized below.

The old series is based on an expenditure pattern of 1951, whereas the new series will be calculated according to an expenditure pattern of 1959/'60. The latter data will be derived from a budget survey held among 250 households of manual and clerical workers consisting of 4 persons and grossing between four and eight thousand guilders a year (para. 6). The period covered was April 1959 till April i960.

The author indicates the way in which the varieties of the budget items to be covered by the monthly price surveys are chosen (para. 7). He discusses the principles and results of determining the number of price quotations (para. 8).

The choice of the municipalities in which price data will be collected is explained. An outline is given of the organisation of the new surveys apparatus (para. 14).
Assortimentsbepaling van seizoenprodukten
Authors: Meerendonk H. W. v. d. , Bos G. G. j.
Published: April 2008

This paper deals with the analysis of a problem often met when determining purchasing policies. From a number of different kinds of goods, which are to be bought, the total quantity is restricted by storing capacity or financial limits. The problem “how much of each kind will be bought” is solved for a discrete as well as for a continuous distribution of demand for the various goods.
Van geval tot geval met als metgezel net getal*
Authors: van Ettinger J.
Published: April 2008

In this lecture the promoter of the Netherlands Statistical Union presents some thoughts about “facts and figures”, as considered by the statistician.

All people have to do with facts, important, remarkable, funny or whatever they may be. People meet also figures, small, great or peculiar. But the statistician has to look at facts and figures in combination. Facts to be expressed typically in figures and figures to be used in forecasting future.

The combination of knowledge about facts by figures contains important possibilities, but also some danger.

The above is demonstrated in a great number of practical applications.
Gevallen van getallen in een bedrijf*
Authors: Wijvekate M. L
Published: April 2008

Data can be divided into right and wrong data, exact and inaccurate data, random and biased data. The most practical division is that into usefull and useless data. The usefullness of data depends upon the situation in which the data are used. Such a situation is mostly a decision situation and can be analysed into a number of decision elements. First of all there is a range of possible choices, there must be some decision purpose, the decision must be based on decision information and finally the decision is made by applying some decision function. We must judge our data in relation to their role of decision information in a decision situation. Sometimes we are able to improve the information, sometimes it is possible to adapt the decision funtion to the value of the information. Various examples are given: errors of measurement in sorting, planning the capacity of a new plant, (minimax principle), decision based upon the result of an experiment (using estimate intervals in stead of statistical significance).