ABSTRACT

The previous chapters have dealt almost exclusively with hypothesis

testing techniques for the analysis of contingency tables. In this

chapter an alternative approach w i l l be considered, namely that of

fitting models and estimating the parameters i n the models. T h e

term model refers to some 'theory' or conceptual framework about

the observations, and the parameters in the model represent the

'effects' that part icular variables or combinat ions of variables have

in determining the values taken by the observations. Such an

approach is common i n many branches of statistics such as regression

analysis and the analysis of variance. M o s t c o m m o n are linear models

which postulate that the expected values of the observations are

given by a linear combina t ion of a number of parameters. Techniques

such as maximum l ike l ihood and least squares may be used to

estimate the parameters, and estimated parameter values may then

be used in identifying which variables are of greatest importance i n

'predicting' the observed values.