Towards understanding variety in knowledge intensive business services by distinguishing their knowledge bases

•We aim to understand variety among knowledge intensive business services (KIBS) by differentiating their knowledge bases.•We apply content analysis to empirically identify firms by their primary ‘knowledge type’.•Our methodology is successful in identifying ‘analytical’ and ‘symbolic’ knowledge bases.•Identifying firms by ‘knowledge base’ helps ‘explain’ which firms invest in R&D and design, and helps explain their innovation activity.•Firms with different primary ‘knowledge bases’ use different ‘drivers of innovation’.