During the summarization process, video segments are ranked based on computed similarity measures between the user profile and the movie features. Personalized movie summarization can be seen as “the process of measuring the similarity score of each video segment for the given user preferences and selecting those top ranked segments that will increase the cumulative similarity score of the summary” (Kannan et al., 2015).
First, the similarity between each shot and the user preferences on actor appearance, genre, and visual descriptors is calculated using cosine similarity measures. Each shot is stored as a vector of its features in a high-dimensional space, after which the angles between the vectors are calculated as the cosine similarity between the vectors. After this, user profiles are created based on their ratings on the same features on movies and the similarity between a shot and a user is computed similarly. This should return a ranked list of shots to select for that specific user.

3.5 Evaluation
In accordance with previous studies on automatically generated movie trailers, a qualitative user study will be performed to evaluate the summarization system. This presents the “cold-start” problem of recommendation, as there will be no data on the users in question. To alleviate this problem, the most direct way is to make a rapid profile of a new user by asking for explicit ratings after presenting a number of movies to the user.
In an online questionnaire format, 20-50 users will first be given 20 movies to rate, after which they will receive a personalized movie trailer to evaluate. In accordance with Kannan et al. (2015) and Xu and Zhang (2013), users will be asked to evaluate a personalized trailer, a generic trailer and a trailer with randomized shots on the following points: personalization, plot introduction, character introduction, and attendance likelihood.