Information seeking (IS) has become a critical activity in video-based environments. Up to now, the effects of support on information seeking (i.e., scaffolding) have seldom been assessed. The twofold aim of the current study was to (a) assess the effects of scaffolding on IS in videos and (b) determine the characteristics of the users' mental models after an IS activity with or without scaffolding. We divided 50 participants into two groups that either did or did not benefit from initial scaffolding during an IS task. Both groups then had to perform a localization task without any further access to scaffolding. Results showed that scaffolding the video by providing a table of contents and markers on a timeline helped students to engage in highly efficient IS, but they had less accurate mental representations of the video than those without scaffolding. The hypothesis that scaffolding provides a usable but external model was therefore supported.