Research on effectively searching scientific workflows is limited. Existing work assumes that once workflow data is stored in a database, standard query languages can be directly used to access the data. Several challenges remain to be addressed in order to provide effective access to scientific workflows. First, workflows have unique structure, and a user query should be able to specify the structure of target workflows. Second, search requirements can be diverse according to user needs. Sometimes a scientific user knows exactly what s/he is looking for, and prefers to issue a sophisticated structured query over complex workflow data in order to obtain precise search results. In other cases, scientists do not have a clear idea of what they are searching for, and/or enjoy a simple search mechanism without needing to understand complex data schemas and query languages. The work is planned to enable semantic keyword search on scientific workflows, where relevant search results will be intelligently inferred and returned in ranked order and to design a user-friendly and expressive query language by which users can express precise and sophisticated queries to retrieve scientific workflows. Common types of searches will be used to identify the logical operators that are essential to express these searches. Various indexing and labeling schemes will be designed to speed up processing. The proposed project will benefit scientists by enabling effective and efficient access to scientific workflows in a repository, so that they can reuse existing workflow designs, compare and analyze several workflows, and design new workflows guided by existing ones. By providing effective access to a scientific workflow repository, this research facilitates data sharing and collaborations among teams. The proposed project will not only make significant contributions to fundamental techniques for managing scientific workflows, but also deliver a generic and scalable system for scientific users to search workflows, thereby benefiting scientific collaboration. There are also significant educational and training objectives.
