Search tactics as means of examining search processes in collaborative exploratory web search

Investigations on search processes can either be at macro-level or micro-level. The macro-level investigation focuses on establishing theoretical models while micro-level investigation focuses on the user actions. In this paper, we propose using search tactics as means of examining search processes in collaborative exploratory search, which can be seen as a middle layer between the macro-level and micro-level. We reported a user study in which participants worked on exploratory Web search tasks using our CollabSearch system under two conditions: collaborative and individual. Using the two methods - action pairs and Hidden Markov Model (HMM) to model search tactics, we discovered some insights about the different patterns of search tactics that participants explored under collaborative and individual search conditions. In the future, we plan to improve the HMM model as a semi-automatic way to detect search tactics. In this study, we further analyze a particular search tactic - query reformulation in collaborative search and discovered the possible sources of new query terms. In the future, we plan to implement a query suggestion algorithm to better support team users' query reformulation tactics. This study provides some guidance for designers on the range of behaviors and activities that a collaborative search system should support. Further studies are needed to fully understand them.