We used our new method to evaluate three different models built using an enlarged set of the brain data containing 104 affine aligned images. It has been shown previously [14,11] that an appearance model can be built by registering each image in a set (pairwise) to a reference image. In  it was argued that a 'groupwise' approach which took proper account of the whole set of images might be expected to perform better. We built three models, one using the pairwise approach, and two variants of our groupwise approach. The results, including the effect of including different numbers of modes in the models, are shown in Figure 9 and demonstrate a clear advantage in terms of both Specificity and Generalisation for both groupwise methods over the pairwise approach. It was not possible to discriminate between the two groupwise methods.