Aggregated Search Over Personal Process Description Graph

People share various processes in daily lives on-line in natural language form (e.g., cooking recipes, "how-to guides" in eHow). We refer to them as personal process descriptions. Previously, we proposed Personal Process Description Graph (PPDG) to concretely represent the personal process descriptions as graphs, along with query processing techniques that conduct exact as well as similarity search over PPDGs. However, both techniques fail if no single personal process description satisfies all constraints of a query. In this paper, we propose a new approach based on our previous query techniques to query personal process descriptions by aggregation - composing fragments from different PPDGs to produce an answer. We formally define the PPDG Aggregated Search. A general framework is presented to perform aggregated searches over PPDGs. Comprehensive experiments demonstrate the efficiency and scalability of our techniques.