Public participation in scientific research (PPSR) involves the involvement of the public in scientific processes, often leading to diverse outcomes in conservation, ecology, and environmental management. This paper reviews and integrates recent work across various fields to propose PPSR as a framework for understanding initiatives from different traditions. Three predominant models of PPSR are described, emphasizing the degree and quality of public participation in influencing project outcomes. A framework is presented to consider how scientific and public interests are negotiated for project design toward multiple, integrated goals. This framework and models can support deliberate design of PPSR efforts to enhance outcomes for scientific research, individual participants, and social-ecological systems. PPSR projects have emerged from various social and academic fields, including participatory action research, citizen science, and community-based monitoring. These projects aim to address complex social-ecological questions and can lead to outcomes such as scientific findings, skill development for participants, and policy changes. However, individual projects may not always consider all three categories of outcomes, which can limit their effectiveness in addressing complex problems. Additionally, project activities may not always align with intended outcomes, and some may achieve unanticipated results. The paper outlines how PPSR project design relates to project outcomes, drawing on work from varied fields. It describes three predominant programmatic models of PPSR and their potential outcomes. The paper also explores the importance of the degree and quality of participation in influencing outcomes. The degree of participation can be quantified and compared, while the quality of participation involves factors such as credibility, fairness, responsiveness, relevance, agency, and due diligence. The paper presents five project models based on the degree of participation: contractual, contributory, collaborative, co-created, and collegial. Each model describes different levels of public involvement in the research process. The contractual model involves communities asking professional researchers to conduct specific investigations, while the collegial model involves non-credentialed individuals conducting research independently. The other three models align with categories recently defined by other scholars. The paper also presents a common framework for deliberate PPSR design, emphasizing the quality of participation and the management of interests addressed through a project. This framework considers how scientific and public interests are negotiated for project design toward multiple, integrated goals. The framework is illustrated with case examples from contributory and co-created projects, showing how different models of participation fit within the framework. The paper discusses the importance of inputs, activities, outputs, outcomes, and impacts in PPSR projects. Inputs include the interests of both the public and the scientific community, while activities involve the work necessary to design, establish, and manage all aspects of a project. Outputs are the initial products or results of activities, while outcomes are measurable elements resulting from the specific outputs of a project. Impacts are long-term and sustained changes that support improved human well-being or conservation of natural resources. The paper concludes that the quality of participation is fundamental to the design process, and that the framework andPublic participation in scientific research (PPSR) involves the involvement of the public in scientific processes, often leading to diverse outcomes in conservation, ecology, and environmental management. This paper reviews and integrates recent work across various fields to propose PPSR as a framework for understanding initiatives from different traditions. Three predominant models of PPSR are described, emphasizing the degree and quality of public participation in influencing project outcomes. A framework is presented to consider how scientific and public interests are negotiated for project design toward multiple, integrated goals. This framework and models can support deliberate design of PPSR efforts to enhance outcomes for scientific research, individual participants, and social-ecological systems. PPSR projects have emerged from various social and academic fields, including participatory action research, citizen science, and community-based monitoring. These projects aim to address complex social-ecological questions and can lead to outcomes such as scientific findings, skill development for participants, and policy changes. However, individual projects may not always consider all three categories of outcomes, which can limit their effectiveness in addressing complex problems. Additionally, project activities may not always align with intended outcomes, and some may achieve unanticipated results. The paper outlines how PPSR project design relates to project outcomes, drawing on work from varied fields. It describes three predominant programmatic models of PPSR and their potential outcomes. The paper also explores the importance of the degree and quality of participation in influencing outcomes. The degree of participation can be quantified and compared, while the quality of participation involves factors such as credibility, fairness, responsiveness, relevance, agency, and due diligence. The paper presents five project models based on the degree of participation: contractual, contributory, collaborative, co-created, and collegial. Each model describes different levels of public involvement in the research process. The contractual model involves communities asking professional researchers to conduct specific investigations, while the collegial model involves non-credentialed individuals conducting research independently. The other three models align with categories recently defined by other scholars. The paper also presents a common framework for deliberate PPSR design, emphasizing the quality of participation and the management of interests addressed through a project. This framework considers how scientific and public interests are negotiated for project design toward multiple, integrated goals. The framework is illustrated with case examples from contributory and co-created projects, showing how different models of participation fit within the framework. The paper discusses the importance of inputs, activities, outputs, outcomes, and impacts in PPSR projects. Inputs include the interests of both the public and the scientific community, while activities involve the work necessary to design, establish, and manage all aspects of a project. Outputs are the initial products or results of activities, while outcomes are measurable elements resulting from the specific outputs of a project. Impacts are long-term and sustained changes that support improved human well-being or conservation of natural resources. The paper concludes that the quality of participation is fundamental to the design process, and that the framework and