In 1980, Gary and Janice Burke introduced a theoretical model under the mentorship of Mary Reilly to fill a gap in understanding and addressing clients with disabilities’ psychosocial challenges in the rehabilitation process (Kielhofner & Burke, 1980). This groundbreaking theory, the Model of Human Occupation (MOHO), is currently the most widely used theory in occupational therapy research and practice. This model presented practitioners with a conceptual framework and practical tools to guide their assessment and reasoning process, effect change, and measure the impact of their intervention. It guides occupational therapy practitioners to consider the personal values and interests, roles and responsibilities, and environmental contexts of each client.

The model also provided a foundation for program development and research initiatives. Gary’s book, Model of Human Occupation: Theory and Application, now in its fourth edition, has served to educate generations of occupational therapy students (Kielhofner, 2008). More than 500 articles, books, and chapters have reported research, case studies, intervention approaches, and programs based on MOHO.

Gary’s work in developing and validating MOHO led to an interest in the translational dilemma of how theory and empirical evidence can be better integrated into everyday rehabilitation practice. He led the development of a vision, “the scholarship of practice,” which is guiding the current research, curriculum, and teaching of occupational therapy researchers, educators, and practitioners around the world (Kielhofner, 2005b). Gary shared his vision in a keynote address at the 2002 World Federation of Occupational Therapy congress in Stockholm and later in an article in the American Journal of Occupational Therapy (AJOT) titled “Scholarship and Practice: Bridging the Divide” (Kielhofner, 2005a). He was appointed as an associate editor of AJOT, heading a department on clinical scholarship. In 2005, he co–guest edited a special issue of Occupational Therapy in Health Care on the scholarship of practice (Kielhofner & Crist, 2005). In 2006, Gary published the comprehensive text Research in Occupational Therapy: Methods of Inquiry for Enhancing Practice, which examines the convergence of positivistic, phenomenological, and humanistic modes of inquiry and how they can inform and shape practice (Kielhofner, 2006).

Evidence of the influence of Gary’s vision to promote large-scale change and to increase the power of occupational therapy in the health care system was evident in the 2010 symposium Strategies for Enhancing the Role of Occupational Therapy in Mental Health Care: Lessons From the United Kingdom. Leaders from around the world attended this event, including the AOTA president and president-elect, who noted that they were energized to take action to enhance the role of occupational therapy in mental health settings in the United States.

Gary was a prolific writer and had a passion for sharing his knowledge. He published his first book in 1983 and subsequently published 20 books and more than 140 articles in professional journals, as well as 26 book chapters. His books have been translated into German, Japanese, Swedish, Dutch, Spanish, and Portuguese. His three major texts, Model of Human Occupation: Theory and Application; Conceptual Foundations of Occupational Therapy; and Research in Occupational Therapy: Methods of Inquiry for Enhancing Practice, have sold more than 110,000 copies. Conceptual Foundations of Occupational Therapy (Kielhofner, 2009) is the most widely followed theoretical text in occupational therapy. It serves not only as a textbook but also as the framework for curriculum design for hundreds of occupational therapy programs worldwide. Gary’s texts reflect his commitment to preparing students and therapists to use practice models and theories to undergird and guide their practice.

In his efforts to create clinical assessments, Gary became a leading scholar in the development of rehabilitation measures. Gary, his students, and his colleagues have authored 21 assessments based on MOHO that are used around the world in all areas of occupational therapy practice and disseminated through the Model of Human Occupation Clearinghouse (www.moho.uic.edu). His work combined rigorous latent trait modeling with a participatory approach that involved clients and therapists as partners in creating methodologically valid and utilitarian assessments. These assessments are used to assist people with various disabilities and chronic health conditions, ranging from war veterans to children with developmental delays and adults with mental illness. Because of Gary’s interest in cross-cultural aspects of assessments, his psychometric projects ordinarily involved testing in multiple languages and cultures. These assessments have been translated into Spanish, Japanese, German, and 16 other languages.

In the mid-1980s, Gary began a relationship with Swedish scholars that has transformed occupational therapy research and practice in Sweden. As a result of his efforts, the occupational therapy program, which was originally housed in a School of Caring Sciences (roughly equivalent to a community college in the United States), became a full academic department within the Karolinska Institute, Sweden’s leading health university. He replicated these efforts at the University of Linköping, where, in recognition of his scholarship and his contributions to the development of occupational therapy scholarship in Sweden, he was awarded an honorary Doctor of Medicine degree and appointed guest professor in 2010.

In addition to his own scholarly work, Gary was a leader in the development of systems to facilitate research. He had continuous extramural funding for more than 20 years, serving as principal investigator or coinvestigator on approximately $7 million of funded research. Two of his later grants focused on postdoctoral training and reflected his priority of preparing future researchers. He conceived of and received 9 years of funding from AOTA and the American Occupational Therapy Foundation (AOTF) for the Center for Research and the Center of Outcomes Research and Education (CORE) at UIC, which focused on practice scholarship, particularly psychometric development of clinical assessments and studies of intervention impact. In the last years of its funding, the center brought together key researchers from North America and Europe to enhance their preparation to conduct outcomes research. Gary was the main mentor to CORE researchers, supporting junior researchers in their grant-writing and publication activities. As a dedicated mentor, he knew how to maximize the success of those he guided. Participants in the center generated more than $15 million in research funding aimed at examining practice outcomes. Gary’s approach was so successful that he was invited by colleagues in the United Kingdom to develop the United Kingdom Center for Outcomes Research and Education (UKCORE) in 2002, which was built on the philosophy of the scholarship of practice. This center has active relationships with health care trusts in England and Scotland and brings together more than 1,000 practicing therapists with researchers to advance scholarship and practice improvement and impact simultaneously. By 2010, UKCORE had secured more than $4.5 million of research funding to underpin its work and used 20 researchers.

Gary’s outcomes research also expanded to program development and evaluation of interventions. Gary was one of the field’s leading scholars in the area of intervention outcomes research. His published empirical reports of practice outcomes spanned nearly three decades, and his research included evaluating the vocational and independent living outcomes of services for people with mental illness and with HIV/AIDS. CORE and UKCORE have had an unparalleled impact on the generation of evidence about the outcomes of occupational therapy practice. In 2004, Gary developed and contributed to a special issue of AJOT focused on the state of the art in outcomes research in the field (Kielhofner, Hammel, Finlayson, Helfrich, & Taylor, 2004).

Gary contributed in major ways to the development of graduate programs in the College of Applied Health Sciences at UIC. He led the Department of Occupational Therapy through the development and approval of the professional Master of Science in Occupational Therapy degree program, which has consistently been ranked in the top four in the nation by U.S. News and World Report. Gary was a key developer of the college’s PhD program in Disability Studies in 1998, the first of its kind in the United States. In 2006, he led the UIC faculty in developing an innovative clinical Doctor of Occupational Therapy degree that was the first clinical doctorate in occupational therapy in the country offered at a public university.

Gary was honored with many of the highest academic awards in his field. He was 1 of 12 charter members elected to AOTF’s Academy of Research. He received AOTF’s A. Jean Ayres award, which recognizes the highest contributions to theory development in the field. He was named an AOTA Fellow in 1983. Gary also was recognized outside the profession, receiving three honorary doctoral degrees (two in Europe and one in the United States). He received the UIC University Scholar award in 2004, the university’s highest academic award for research achievement, given to fewer than 1% of university faculty members. He was named Professor of the Year of the College of Applied Health Sciences in 2009.

Gary Kielhofner was a remarkable man, a visionary, and a passionate scholar. Gary’s work has inspired and affected the lives of thousands of therapists, students, clients, and colleagues. He made history, broke ground, and shaped the future of the profession. He shared a unique sense of pride and unbridled enthusiasm when mentoring students and colleagues, bringing out the best in them, often more than they saw in themselves. As a visionary, he thought of a world of peace, in which social justice reigns and individual occupational performance needs are met.

Gary touched many lives. He planted seeds everywhere he went and reached thousands of people through his published works and speaking engagements as well as in the day-to-day interactions that he valued so much. He provided the fire for others to create for themselves, to be inspired, and to take part in new endeavors. As we look into the future, we are committed to continuing his legacy and promoting his work.