We report a detailed study of the implementation of "Tutorials in Introductory Physics" at a large-scale research institution. Based on two successive semesters of evaluation, we observe students' improved conceptual mastery (force and motion concept evaluation median normalized gain 0.77, N=336 ), albeit with some student discontent. We replicate the results of original studies of tutorial effectiveness and document how and why these results occur. Additionally, using the Colorado Learning Attitudes about Science Survey we measure the support of students' expertlike beliefs about learning physics in our environment. We examine this implementation from a viewpoint that emphasizes varying contextual levels of this implementation, from students' engagement in individual tasks, to the situations in which these tasks are embedded, to the broader classroom, departmental, and educational structures. We document both obvious and subtle features that help ensure the successful implementation of these reforms. (Contains 67 endnotes, 3 tables and 5 figures.)