This report assesses the impact of instruction in online bibliographic database searching on high school students' use of library materials and facilities in three Delaware secondary schools (one public, one parochial, and one private) during the spring of 1984. Most students involved in the analysis were given a brief explanation of online bibliographic searching and instruction in search strategy. They were encouraged to prepare a search request for the topic they had selected for their research assignment. The databases used were selected by a professional librarian. Completed searches, containing documents of potential use to the students, were returned to the students. A critical incident analysis was conducted on the following data: copies of the bibliographies of the student papers (132); questionnaires completed by students in class at the time assignments were due (175); records of student searches (111); and interviews with cooperating school library media specialists (7 teachers and 3 librarians). Following an introduction, discussion of rationale, and description of evaluation design, this report presents observations and implications from data analysis on the following topics: student use of facilities; student material preferences; school library role in delivering documents; age of books used; currency of magazines used; focus of magazine use; use of online references; currency of online references; the most heavily used database; and cost of online searching. Sections on clarifying educational objectives and a summary and recommendations are included. Numerous appendices and tables support the research report. (THC)