Before getting into the details of the analysis we should briefly look at the kind
of data analyses that have been used in OM. Scudder and Hill (1998) analysed the
method used in 477 OM empirical research articles published during the period
1986-1995 in the 13 main journal outlets for OM research. They found that 28 per
cent of articles did not use any statistical data analysis method (almost all of
these articles were based on case studies), while some articles used more than one
data analysis method. Furthermore they found that 72 per cent of articles used
descriptive statistics, 17 per cent regression/correlation, 9 per cent means testing,
7 per cent data reduction (principal component analysis, etc.), 4 per cent ANOVA
and MANOVA, and 3 per cent cluster analysis.