Enhancing creativity has been paid a lot of attention recently, especially with the emergence of online collaborative ideation. Prior work has shown that, in addition to the exposure of diverse and creative examples, visualising the solution space enables ideators to be inspired and, thus, arrive at more creative ideas. However, existing automated approaches which assess the diversity of a set of examples fail on unstructured short text due to their reliance on similarity computation. Furthermore, the conceptual divergence cannot be easily captured for such representations. This research in progress introduces an approach based on semantic annotation to overcome these issues. The solution proposed formalizes user ideas into a set of annotated concepts and a matching mechanism is then used to compute the similarity between users' ideas. We aim also to create a visualisation of the solution space based on the similarity matrix obtained by a matching process between all ideas.