The document discusses the ecological model of health behavior. It provides a history of ecological models emerging from various disciplines that converged to form the foundations of health promotion. The core concepts are described as behavior being influenced by multiple levels, including intrapersonal, interpersonal, organizational, community and public policy levels. Applications to tobacco control and diabetes management are outlined at each level. Strengths include a focus on multiple influences and environmental/policy interventions, while weaknesses involve lack of specificity about influences and interaction across levels.