Search and result presentation in scientific workflow repositories

Abstract

We study the problem of searching a repository of complex hierarchical workflows whose component modules, both composite and atomic, have been annotated with keywords. Since keyword search does not use the graph structure of a workflow, we develop a model of workflows using contextfree bag grammars. We then give efficient polynomial-time algorithms that, given a workflow and a keyword query, determine whether some execution of the workflow matches the query. Based on these algorithms we develop a search and ranking solution that efficiently retrieves the top-k grammars from a repository. Finally, we propose a novel result presentation method for grammars matching a keyword query, based on representative parse-trees. The effectiveness of our approach is validated through an extensive experimental evaluation.

Effective and efficient similarity search in scientific workflow repositories

“…The authors report runtimes of 15 seconds over a repository of 89 workflows and manually evaluate retrieval quality on an example workflow (explicitly rejecting to derive generic claims). In [7] workflows are represented as context free bag grammars. This allows effective matching of keywords specified in an user's query against the (possible) executions of a workflow and the corresponding execution traces of its modules.…”