nalytical corrections have been derived for a beam theory analysis for the adhesively bonded tapered double cantilever beam test specimen to account for the effects of beam root rotation and for the real, as opposed to idealised, profile of the beam as required experimentally. A number of adhesive–substrate combinations were tested according to a new test protocol and the new analysis method for data reduction is compared critically with the existing simple beam theory and experimental compliance approaches. Correcting the beam theory for root rotation effects is shown to be more important than correcting only for the effects of shear deformation of the substrates. Results from a finite element analysis, using a cohesive zone model, also showed close agreement with the proposed new corrected beam theory analysis method.