Comparative evaluation of rule-based and case-based retrieval coordination for search of architectural building designs

To support the early conceptualization phase in architecture with computer-aided solutions, in particular, with retrieval systems that can find similarly structured building designs in comprehensive collections of such designs, a number of approaches were presented to date. In the Metis project two retrieval coordination approaches (coordinators) were developed to govern the search of similar (sub-)structures of architectural designs. The main task of both coordinators is to select the retrieval method that is appropriate for the given user query. First approach is a standalone service that uses rules only to coordinate the retrieval and can use subgraph matching and database search methods, whereas the second one is rule- and case-based and is part of a distributed system for case-based retrieval of architectural designs. We compared both coordinators in a user study to find out which strengths and weaknesses both coordinators currently possess, and for which retrieval scenarios of the architectural conceptualization phase they could be appropriate. The results showed that the complexity of the particular scenario and the purpose of search are the main points that differentiate both coordinators. The rule-based coordinator performed better when a search for exact (sub-)structures was required, whereas the rule- and case-based coordinator is appropriate for queries aimed to be used for exploration and general search for inspiration. Visualization of the results of both coordinators is in need of improvement.