 To consider an example which is much discussed in the research ethics literature, it is commonly assumed that valid consent for randomized clinical trials requires individuals to understand randomization. It requires individuals to understand that the treatment they will receive, if they enroll in the study, will be determined by a process which does not take into account which of the treatments is better for them (Kupst 2003). There is an impressive wealth of data which suggests that many, perhaps most individuals who participate in clinical research do not understand this (Snowden 1997; Featherstone and Donovan 2002; Appelbaum 2004). The data also suggest that these failures of understanding often are resistant to educational interventions.