It looks as if one interview was done with the cluster manager in the six regions, but the authors also claim to have interviewed ‘the presidents of cluster firms’ (p. 8, line 20) without indicating the number.
According to the definition on the top of page 4, the term denotes a cluster led by a public research organisation, which is rather specific and I doubt it applies to the six case studies outlined in the paper. Even so, the term ‘intellectual’ does not look fully appropriate here, which may be due to its translation from a Japanese original. ‘Public research-led cluster’ might be more to the point, as it appears difficult to judge if these are more or less ‘intellectual’ than other forms of clusters. At the least, it would appear sound to qualify these six cases as science-based clusters, but then this would apply to the biotech industry and all its clusters in general.