The Indianapolis-Marion County Public Library's summer reading program aims to help children develop a love of reading by giving them full control over what and how much to read. A study examined the effects of the 1990 program, with special attention to low-achieving students. A quantitative analysis was undertaken of 164 first- through sixth-grade students' pre- and post-test reading achievement in the reading program (together with 16 students who served as a control group) chosen randomly from the 4,000 students served by 9 branch libraries in the inner-city area of Indianapolis, Indiana. The descriptive portion of the study involved surveys and interviews of the 164 students, their parents, and the librarians from the 9 branch libraries. Seven low-achieving students involved in the quantitative portion of the study were selected as subjects for case study. Results indicated that: (1) students maintained their reading achievement levels over the summer, whether or not they were involved in the reading program; (2) the reading program attracted mainly average and above-average readers; (3) the incentives offered were effective but not necessarily linked to the amount of reading completed by the children; (4) participants enjoyed positive experiences with the public library; and (5) a notable proportion of participants reported visiting the library with parents or other family members and/or engaging in reading activities with family members outside the library. (Nine tables of data are included; participant and control group survey forms and results, parent telephone survey form and results, individual case study stories, and 41 references are attached.) (RS)