The purpose of this research is to examine the connections between self-efficacy beliefs about mathematics and participation. The sample for this study (n = 16) was purposefully selected from two Algebra I classrooms in a Midwestern high school. From the 16 target participants, eight were female and eight were male. The focus of the study was the participation of the females while they worked in cooperative groups on open-ended, reform-oriented tasks as suggested by the National Council of Teachers of Mathematics (NCTM). Videotapes, surveys, and interviews were utilized as sources of data for the study. It was found that females who report low self-efficacy at the beginning of the semester generally increased in their confidence to work successfully on mathematics problems through the course of their participation. Other findings indicate that this holds for not only the females reporting low efficacy, but males also. Increases in participation also occurred for those who reported increases in mathematical and social self-efficacy. Utilizing scenarios that are outlined in this study may inform pre-service and in-service teachers of classroom practices that may be helpful in retaining those who have low perceptions of their ability, specifically underrepresented populations. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]