Community-engaged research (CEnR) is the process of working collaboratively with groups of people affiliated by geographic proximity, special interests, or similar situations with respect to issues affecting their well-being. One of the most widely used forms of community-engaged research is community-based participatory research (CBPR), though it also encompasses action research and participatory action research. Another form of community-engaged research is integrated knowledge translation (iKT), defined as "an approach to doing research that applies the principles of knowledge translation to the entire research process". The iKT evolves around the concept of engaging different levels of knowledge users (community members, organizations working in the community, and policy makers) as equal partners in the research activities so that research outputs are more relevant to, and more likely to be useful to, the knowledge users.

Community-based participatory research (CBPR) is an equitable approach to research in which researchers, organizations, and community members collaborate on all aspects of a research project. CBPR empowers all stakeholders to offer their expertise and partake in the decision-making process. CBPR projects aim to increase the body of knowledge and the public's awareness of a given phenomenon and apply that knowledge to create social and political interventions that will benefit the community. CBPR projects range in their approaches to community engagement. Some practitioners are less inclusive of community members in the decision-making processes, whereas others empower community members to direct of the goals of the project.

Participatory action research (PAR) is an approach to action research emphasizing participation and action by members of communities affected by that research. It seeks to understand the world by trying to change it, collaboratively and following reflection. PAR emphasizes collective inquiry and experimentation grounded in experience and social history. Within a PAR process, "communities of inquiry and action evolve and address questions and issues that are significant for those who participate as co-researchers". PAR contrasts with mainstream research methods, which emphasize controlled experimentation, statistical analysis, and reproducibility of findings.

PAR practitioners make a concerted effort to integrate three basic aspects of their work: participation (life in society and democracy), action (engagement with experience and history), and research (soundness in thought and the growth of knowledge). "Action unites, organically, with research" and collective processes of self-investigation. The way each component is actually understood and the relative emphasis it receives varies nonetheless from one PAR theory and practice to another. This means that PAR is not a monolithic body of ideas and methods but rather a pluralistic orientation to knowledge making and social change.

PAR emerged in the postwar years as an important contribution to intervention and self-transformation within groups, organizations and communities. It has left a singular mark on the field of rural and community development, especially in the Global South. Tools and concepts for doing research with people, including "barefoot scientists" and grassroots "organic intellectuals" (see Gramsci), are now promoted and implemented by many international development agencies, researchers, consultants, civil society and local community organizations around the world. This has resulted in countless experiments in diagnostic assessment, scenario planning and project evaluation in areas ranging from fisheries and mining to forestry, plant breeding, agriculture, farming systems research and extension, watershed management, resource mapping, environmental conflict and natural resource management, land rights, appropriate technology, local economic development, communication, tourism, leadership for sustainability, biodiversity and climate change. This prolific literature includes the many insights and methodological creativity of participatory monitoring, participatory rural appraisal (PRA) and participatory learning and action (PLA) and all action-oriented studies of local, indigenous or traditional knowledge.

On the whole, PAR applications in these fields are committed to problem solving and adaptation to nature at the household or community level, using friendly methods of scientific thinking and experimentation adapted to support rural participation and sustainable livelihoods.

Feminist research and women's development theory also contributed to rethinking the role of scholarship in challenging existing regimes of power, using qualitative and interpretive methods that emphasize subjectivity and self-inquiry rather than the quantitative approach of mainstream science. As did most research in the 1970s and 1980s, PAR remained androcentric. In 1987, Patricia Maguire critiqued this male-centered participatory research, arguing that "rarely have feminist and participatory action researchers acknowledged each other with mutually important contributions to the journey." Given that PAR aims to give equitable opportunity for diverse and marginalized voices to be heard, engaging gender minorities is an integral pillar in PAR's tenants. In addition to gender minorities, PAR must consider points of intersecting oppressions individuals may experience. After Maguire published Traveling Companions: Feminism, Teaching, And Action Research, PAR began to extend toward not only feminism, but also Intersectionality through Black Feminist Thought and Critical Race Theory (CRT). Today, applying an intersectional feminist lens to PAR is crucial to recognize the social categories, such as race, class, ability, gender, and sexuality, that construct individuals' power relations and lived experiences. PAR seeks to recognize the deeply complex condition of human living. Therefore, framing PAR's qualitative study methodologies through an intersectional feminist lens mobilizes all experiences – regardless of various social categories and oppressions – as legitimate sources of knowledge.

Novel approaches to PAR in the public sphere help scale up the engaged inquiry process beyond small group dynamics. Touraine and others thus propose a 'sociology of intervention' involving the creation of artificial spaces for movement activists and non-activists to debate issues of public concern. Citizen science is another recent move to expand the scope of PAR, to include broader 'communities of interest' and citizens committed to enhancing knowledge in particular fields. In this approach to collaborative inquiry, research is actively assisted by volunteers who form an active public or network of contributing individuals. Efforts to promote public participation in the works of science owe a lot to the revolution in information and communications technology (ICT). Web 2.0 applications support virtual community interactivity and the development of user-driven content and social media, without restricted access or controlled implementation. They extend principles of open-source governance to democratic institutions, allowing citizens to actively engage in wiki-based processes of virtual journalism, public debate and policy development. Although few and far between, experiments in open politics can thus make use of ICT and the mechanics of e-democracy to facilitate communications on a large scale, towards achieving decisions that best serve the public interest.

In the same spirit, discursive or deliberative democracy calls for public discussion, transparency and pluralism in political decision-making, lawmaking and institutional life. Fact-finding and the outputs of science are made accessible to participants and may be subject to extensive media coverage, scientific peer review, deliberative opinion polling and adversarial presentations of competing arguments and predictive claims. The methodology of Citizens' jury is interesting in this regard. It involves people selected at random from a local or national population who are provided opportunities to question 'witnesses' and collectively form a 'judgment' on the issue at hand.

ICTs, open politics and deliberative democracy usher in new strategies to engage governments, scientists, civil society organizations and interested citizens in policy-related discussions of science and technology. These trends represent an invitation to explore novel ways of doing PAR on a broader scale.