The use is described of pattern recognition techniques to analyze folded (in w1) 2-dimensional NMR spectra obtained by using the COSY (correlation spectroscopy) technique. A pattern recognition procedure (P. and B., 1986) relying on the comparison of patterns in z-COSY and anti-z-COSY spectra is applied to both normal and reconstructed spectra of a 1:2 mixt. of the cis and trans isomers of 2-phenylcarboxylic acid Et ester as an illustrative example. [on SciFinder (R)]