The fifth Sonsbeek differs from the previous triennial editions in a number of ways. First, for the first time, the committee responsible for selecting the artworks was a committee of sculptors and institutional employees. In the run-up to the exhibition, they faced new challenges. For example, in selecting artworks, they had to take into account the competing Venice Biennale of 1964 and 1966. A greater challenge was the ambition, compared to previous editions, to present a more convincing overview of contemporary developments in sculpture. This proved to be a complicated task, as all sorts of new movements manifest themselves in the 1960s.

What the artists have in common is that they are trying to bring art out of "its lofty isolation," according to Professor Jaffé in the catalog's introduction. The boundary between viewer and artwork blurs both literally - pedestals disappear - and figuratively. As a result, artists are given more freedom to experiment with new techniques and materials. Sonsbeek '66 shows a greater variety of sculptures, in terms of materials, techniques and styles.