This paper brings together some key concepts and proposes a conceptual framework for understanding and evaluating determinants of learning outcomes. The framework facilitates the process of theorizing and hypothesizing on the relationships and processes concerning lifelong learning as well as their antecedents and consequences. The specific aims are to outline a general approach for evaluating learning outcomes, identify data gaps within this approach, and discuss some of the implications for research and development. Along with more specific frameworks, this general approach can be used to guide policy relevant research in education. In particular, it can be used to inform efforts aimed at establishing a coherent information system on the impact of lifelong learning on both economy and society.