Decision-making is a universal process that occurs constantly in life. Parent participation in educational decision-making is recognized as important by special education law, by special education and school psychology literature (Christenson & Sheridan, 2001; IDEIA, 2004;). Partnership in decision-making is especially important for parents of diverse culture and SES, who participate at lower rates, and for whom participation and partnership may mean different things (Epstein, 2001; Gaitan, 2004). Within that population, partnering with parents of children with autism is a priority due to the complex effects of autism on children's communication, socialization, and behavior, a plethora of available resources and interventions, and negotiation of those resources and roles of schools with the expectations of parents. Decisions that diverse parents must make are often complex and their priorities may be different than those of the professionals with whom they work (Dunlap & Fox, 1999; Mandell & Novak, 2005). One method that has been used in the field of medicine, and to a lesser degree in education, is the use of decision-making aids to enhance joint decision-making between patients and providers or between parents and educational professionals (Giangreco, Cloninger & Iverson, 1998; O'Connor et al 2009). However, when these tools are reviewed, few posit a theoretical basis, and when educational decision tools are evaluated using an international quality criteria checklist, they fall short in addressing specific populations and encouraging parents to identify their values and in a process for making decisions, and focus on professionals as the administrator of the tool. This study utilized design research methodology to develop a grounded theory model of IEP decision-making for diverse parents of elementary-aged children with autism in Kansas City, KS public schools and to create a decision aid based in the grounded theory and other sources. Participants report a variety of types of decisions that parents make when working with their IEP team, as well as the interaction and influence of varying layers of child, parent, family, systemic, and relational factors into parents' decision-making process. Participants report four general types of parent response when presented with IEP decisions. In partnership with an Advisory Board comprising parent and professional participants, the grounded theory, decision aid standards, and other resources served as a basis for the design of an IEP decision aid tool. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]