“…The users' behavior and spontaneous reactions to multimedia data can provide useful information for multimedia indexing with the following scenarios: (i) direct assessment of tags: users spontaneous reactions will be translated into emotional keywords, e.g., funny, disgusting, scary [18,13,16,19]; (ii) assessing the relevance of explicit tags or topic relevance, e.g., agreement or disagreement over a displayed tag or the relevance of the retrieved result [8,12,20,21]; (iii) user profiling: a user's personal preferences can be detected based on her reactions to retrieved data and be used for re-ranking the results; (iv) content summarization: highlight detection is also possible using implicit feedbacks from the users [22,23].…”