In this program statistical analysis of ultrasonically determined parameters was used to identify the features of acoustic wave propagation in adhesively bonded structures which could be used to determine adhesive bond strength. The parameters associated with the interaction of ultrasonic waves with the adhesive-aluminum interfaces and adhesive interlayer which were investigated included bondline transit time, amplitude ratios of reflections from the various interfaces, frequency dependent attenuation and spectral resonance characteristics. Aluminum specimens with both etched and as-received surface preparation were studied. The capabilities of the Fokker bondtester for adhesive strength determination were also assessed. Adaptive learning techniques were used to statistically examine correlation between the observed acoustic properties and shear strength for 394 specimens.