This study intends to enhance the understanding of successive searches over multiple sessions by characterizing successive searches with a conceptual model, Multiple Information Seeking Episodes (MISE), validating MISE and supporting successive searches with a prototyped information system, PERsonalized and Successive Information Seeking Toolkit (PERSIST), whose requirements are derived from MISE. The study has both theoretical and practical values as it increases the understanding of human information behavior and develops useful tools to support the concerned behavior.