Main trends of research in the social and human ... - unesdoc - Unesco

Mathematical models and methods 565
increased markedly in the last few years. This increase is on occasion associated
with specific problems. Thus the utility measurement theory was born of needs
engendered by economic theory. But above all the development of measurement
and classification models got its impulsion from psychology and principally
psychometry. Only later did the social psychologists and sociologists
realize the value of measurement and classification models, notably when they
came up against the problem of ‘attitude measurement’.
Spearman, Thurstone, Guttman, Lazarsfeld and many others have lent their
names to classification and measurement models. In most cases the models
consist in the expression of a collection of observable variables (success in tests,
answers to questions about personal attitudes, etc.) as functions of classifying
variables, variously labelled non-observable, latent or genotypic. Thus, in
Spearman’s classical factorial analysis we write that the success zij of a subject
i in a test j is a linear function of an intelligence measure Fi and of the score
eiJ of subject i on a factor peculiar to test j. Accepting certain conventions on
how the variables t?J and Fi are measured, and assuming all latent variables to
be independent, it is possible to test the model and estimate the Fi quantities.
Lazarsfeld’s latent structure analysis can be regarded as an adaptation of
Spearman’s factorial analysis to the cases - frequent in sociology and social
psychology - when the observed variables are qualitative.
Over and above the researches in the direct Spearman lineage, there is another
research tradition which is important in the field of measurement theory,
namely the one deriving from the work of the psychophysicists.
This latter tradition was started by Thurstone in the 1920s, and developed in
greater mathematical depth by writers such as Mosteller between 1950 and
1960; Luce’s recent work on the theory of measurement can also be included.
All these researches present the common characteristic of confronting the
respondent not with isolated questions or stimuli, but with groups of stimuli
whose terms he must compare. These models, which presuppose complicated
observation procedures, are usable principally in experimental situations,
whereas models in the Spearman tradition are better adapted to observation
situations (surveys by questionnaire, psychometrical observations, etc.).
One other tradition, which started from a critical review of the two just
mentioned, is particularly well represented in the works of Guttman and
Coombs. Whereas the models arising from the researches of Spearman and
Thurstone are all statistical models, those of Guttman and Coombs are either
algebraic or combinatorial. They avoid the disadvantages of the assumptions
built into previous models (linear character of the relationships between overt
and latent variables in Spearman’s analysis ; normal distribution hypotheses in
the Thurstone-Mosteller models), but introduce others. In effect, they assume
that the data conform to the model not stochastically but exactly. (To mark the
contrast between the two types of model, the psychosociological measurement
theory relies on a choice of terms which, inasmuch as it may be the source of
all sorts of confusion, is highly debatable: it calls models of the latter type
deterministic, contrasting them with probabilistic models of the Spearman-
Thurstone type.)