I propose four key elements for the sorts of issues Integration and Implementation Sciences are designed to tackle.

Complexity has many dimensions, including an extensive array of factors, with both linear and nonlinear connections and interdependencies, and a range of relevant political, cultural, disciplinary and sectoral perspectives. Geographical and temporal scales can be huge. An important dimension of complexity is identifying and understanding emergence.

A necessary adjunct to complexity is uncertainty. In dealing with any complex issue or problem, there will always be many unknowns, including facts, causal and associative relationships, and effective interventions. Some unknowns result from resource limitations on research and some result from methodological limitations, while some things are simply unknowable. There are epistemological, ethical, organisational and functional aspects to dealing with uncertainty, ignorance and risk.

The unknowns are compounded by constant change, occurring on many fronts including biological evolution (for example, the development of new communicable diseases); scientific, technological and economic developments; changes in international relations; and manifold intended and unintended consequences of local, national and international policy and programs.

Perfect knowledge and solutions are impossible. Imperfection also has many dimensions. Dealing with complexity involves setting boundaries to the approach we take, and where we set boundaries is crucial in determining what is included, excluded and marginalised. Uncertainty and change also necessarily lead to imperfection. Further, social issues are deeply contextualised: an excellent solution in one person’s eyes is anathema to another.