The ethical treatment of cancer patientsparticipating in clinical trials requiresthat patients are well-informed about thepotential benefits and risks associated withparticipation. When patients enrolled in phaseI clinical trials report that their chance ofbenefit is very high, this is often taken as evidence of a failure of the informed consent process. We argue, however, that some simple themes from the philosophy of language may make such a conclusion less certain. First, the patient may receive conflicting statements from multiple speakers about the expected (...) outcome of the trial. Patients may be reporting the message they like best. Second, there is a potential problem of multivocality. Expressions of uncertainty of the frequency type can be confused with expressionsof uncertainty of the belief type. Patients may be informed using frequency-type statements and respond using belief-type statements. Third, each speech episode involving the investigator and the patient regarding outcomes may subservemultiple speech acts, some of which may beindirect. For example, a patient reporting ahigh expected benefit may be reporting a beliefabout the future, reassuring family members,and/or attempting to improve his or her outcome by apublic assertion of optimism. These sources oflinguistic confusion should be considered injudging whether the patient's reported expectation isgrounds for a bioethical concern that there hasbeen a failure in the informed consent process. (shrink)