Abstract: A social network based system is provided to facilitate a user to get the user's progressive ratings on skills over time in reference to concrete reference activity. The system comprises means for a user to build social network for facilitating skill-rating and means for creating a rating request defining a context activity and target skills. The system further comprises means for inviting users of different relationships to user from the user's social network to rate on target skills included in the rating request in reference to the context activity. The system further comprises means for answering an incoming rating request, through which 360-degree rating data over time can be provided on a rating request. The system further comprises means for establishing groups for facilitating skill-rating for organizations. Means are provided to create team rating request through which a group can collect team 360-degree rating data of members over time.