Informed consent is important: in research, it allows subjects to make an informed and voluntary choice to participate--or refuse to participate--in a project where they will be asked to take risks for the benefit of others. In both research and clinical care, informed consent represents a permission to intervene on a person's private sphere. The elements of informed consent are usually described as disclosure, understanding, decision-making capacity, and voluntariness. Each poses distinct difficulties, and can be amenable to improvements. However, research on the quality of informed consent and on strategies intended to improve it have only become the object of research relatively recently. In this article, we describe some results of this research, and outline how they can be relevant to informed consent in research and clinical care. Although much of the data suffers from limitations, it does suggest that disclosure has improved, but is still uneven, comprehension is often poor, for both patients and research subjects. Moreover, trust is a motivating factor for research participation, and thus we run risks if we allow false expectations and prove ourselves unworthy of this trust. Although improving consent forms does not have a clear effect on understanding, improving the consent process may help. Finally, better information may decrease anxiety and seems to have at most a small negative effect on research recruitment.