Toward interactive, Internet-based decision aid for vaccination decisions: better information alone is not enough.

Vaccination decisions, as in choosing whether or not to immunize one's small child against specific diseases, are both psychologically and computationally complex. The psychological complexities have been extensively studied, often in the context of shaping convincing or persuasive messages that will encourage parents to vaccinate their children. The computational complexity of the decision has been less noted. However, even if the parent has access to neutral, accurate, credible information on vaccination risks and benefits, he or she can easily be overwhelmed by the task of combining this information into a well-reasoned decision. We argue here that the Internet, in addition to its potential as an information source, could provide useful assistance to parents in integrating factual information with their own values and preferences - that is, in providing real decision aid as well as information aid. We sketch one approach for accomplishing this by means of a hierarchy of interactive decision aids ranging from simple advice to full-scale decision analysis.