Following a series of investigations undertaken into the methods of written surveys by the authors, this argument can be viewed as correct only up to a certain point. When written surveys are entailed , the requisite degree of evaluation is dependent upon a series of ranges of influences which determine the limits. Points to be born in mind include the type of the target group, the kind of characteristics under survey and the manner of formulation of the questions as well as the way the interrogatory media are set up.
If the volume of the population's demand is defined as that quantity of a certain commodity which consumers intend buying in a certain period of time, we may infer that, effectively, the quantities of commodities bought may be smaller than the volume of demand. Of course, such situations occur when supply is lower than demand. Regardless of the duration of such a situation, one may speak of unsatisfied demand. It is therefore of great interest to investigate such demand. As in the case of satisfied demand, the investigations of unsatisfied demand may be carried out by means of econometric or random sampling methods. Whatever the method used, one should bear in mind that the generic designation "unsatisfied demand" refers to at least three particular cases which must be well defined, so that the right method may be chosen and applied.
A special study consisting of a survey among 326 housewives, has shown that the friendliness effect in product tests is minimised if the method below is used: The interviewer shows three packs with the same contents, but with different code numbers/letters. The housewife is given the suggestion that two of the packs contain a now product and the third pack is the product she is always using, without identifying the packs. The housewife herself selects the pack she will test, presumably under the impression that she has a chance of one third to get the product she is always using. A control group, where all packs contain the product she is always using, interviewed with the same questionnaire, provides the level of the bias which always remains. This level is the zero level for the results of the product test for the new product. With this system the friendliness-bias can be reduced considerably. In this study the reduction of the bias was about 50%.
In the present study, an alternative is offered to the methods of socio-economic stratification. The proposed method is based on the idea that socio-economic status also manifests itself in the level of consumption of the respondents. The study uses data from the survey conducted by the Motherlands Foundation for Statistics in the Netherlands, in 1963 among a representative sample of households, on behalf of Header's Digest. In this study questions were asked relating to the possession of a large number of durable consumer goods and the purchase of a wide variety of commodities.
In October 1968, the Chairman and Managing Director of Alimentare Emiliana S.p.A., Mr. Limentani, had considered the advisability of entering into a new sector of pre-packed foods, for which the prospects of development in Italy seemed to be promising.
The questions posed by delegates , both in the working groups and in the final session on Saturday morning, fell into five main groups: these are summarised below, with the answers given by the authors.
Before reporting upon the discussions of the different contributions, I would like to make some general remarks which result from our discussion group Nr. 3 and which do not refer to the one or the other specific report.
The difference between typology and segmentation was then discussed. The most popular opinion was that: 1. Segmentation implies the isolation of one of the variables as being the one to be predicted; 2. Such restraints are not needed when applying a method of typological analysis; this kind of descriptive analysis therefore permits a total flexibility without any a priori judgment. It remains however that a typology can lead in some cases to directly interpretable segmentations .
This model is purely a financial one. To give the inputs the different departments of the company must have their own models. The advantage of the corporate financial model is to make the different departments aware of the necessity of computing the inputs and to make the lack of information appear.
On the first place, it has to be said that the group members consider it as a jolly good idea to observe the purchasing habits over quite long periods of time instead of making conclusions based on elementary purchasing behaviour. But they regret that the authors have not (or not yet) studied the relationship between the duplications and the D coefficients observed for specified pairs of brands during successive periods. It could be an interesting direction for research to analyse these data on the way it has been done with elementary purchases when applying Markovian processes.
One question which has been raised in the discussion is that of assessing a manufacturer's scope for launching an additional brand in a product-field instead of simply pushing his existing brand. This is in fact one of several kinds of practical application of the results which are already being actively pursued. It links up with the more general topic of studying buyer behaviour for aggregates of brands. This has specific applications not only for judging the scope for additional upper sales limits of existing brands and for assessing the role of house-names, but also provides a link with macro-economics.