Engagement as co-constructing knowledge: A moral necessity in public health research.

Undertaking engagement in public health research is ethically essential. There is a growing emphasis on practicing engagement as the co-construction of knowledge, which goes beyond other common forms of engagement in health research practice: consulting and informing. Taking such an approach means researchers jointly construct knowledge with research users and beneficiaries; all parties design and conduct research together and share decision-making power. This article makes the normative argument that such engagement is necessary to achieve the foundational moral aims of public health research-building relations of equality and addressing the health needs of those considered disadvantaged-which reflect the field's underlying commitment to social justice. It next identifies and discusses three ways in which co-constructing knowledge advances those moral aims: by facilitating self-determination, supporting individuals' right to research, and maximizing social knowledge to address cognitive and epistemic injustice. Objections to the arguments presented in the article are then articulated and defended against.