Contextual Determinants of Electoral System Choice - Ã bo Akademi

4. RESEARCH DESIGN4.1 Method and MaterialThere are four basic methods of establishing general empirical propositions: casestudy, comparative, statistical, and experimental methods (Lijphart 1971: 682). Thescientific status of the case study method is rather ambiguous, because science is ageneralizing activity, but indirectly case studies can contribute to the establishmentof general propositions and to theory-building (1971: 691). The other threemethods aim directly at scientific explanation by establishing general empiricalrelationships among two or more variables while all other variables are controlledfor. The experimental method is an almost ideal method for scientific explanations,but due to practical and ethical impediments it can rarely be used in politicalscience. The statistical method may be considered as an approximation of theexperimental method. Empirically observed data are conceptually manipulated forthe purpose of discovering controlled relationships among variables. The problemof control is handled by means of partial correlation. The only difference betweenthe statistical and the comparative method, according to Lijphart, is that thenumber of cases the latter deals with is too small to facilitate systematic control bymeans of partial correlation. The comparative method should be used when thenumber of cases available makes further cross-tabulation in order to establishcredible controls impossible. No clear dividing line between the statistical and thecomparative method exists; the difference depends completely on the number ofcases (Lijphart 1971: 83-84). C. Anckar asserts that the only clear differencebetween these two methods is that the statistical method uses tests of statisticalsignificance (2004: 3).Because of the similarities between the comparative and the statistical method,these are often regarded as two aspects of a single method. The term ‘comparativemethod’ is quite frequently used for indicating the method of multivariateempirical, but non-experimental, analysis. B. Guy Peters (1998: 10-22)distinguishes between five types of studies that are regarded as components ofcomparative politics. These are (1) case studies of politics in single countries, (2)analyses of institutions and political processes in a limited number of countries, (3)studies developing typologies or other forms of classification schemes forcountries or sub-national units, (4) statistical or descriptive analyses of data from a142