User attention is one of the fundamental indications of users’ interests in search. For content based image search systems, it is important to understand what users pay attention to, and thus engage users more in the search process. It remains a big challenge to design a user-centered interactive interface that serves well for both user interaction and search model, and be able to  bridge the unsolved problem in content-based image search called the Semantic Gap. In an  effort to solve the problem, we designed an interactive content-based image search interface called Search Strategy (SS) based on Vakkari’s model. SS enables users to engage in three stages (pre-focus, focus-formulation, and post-focus) during the search process. We carried out a user study to observe which interface attracts more user attention. The user study is conducted in a lab-based setting using a screen-based eye tracker (Tobii Pro Nano) and Galvanic Skin Response (GSR) on the iMotions platform. The preliminary results show that participant attention is noticeably higher on the SS interface. This finding highlights the need for a welldesigned interface that enables user interaction at all stages of image search process, and at the same time the interface should allow users to manipulate the search model effectively.

Keywords
Content-based image retrieval, user interface, active learning, Vakkari model, eye tracking, query formulation.