clinical rotations and residency training, in which much teaching is done on the basis of an apprenticeship model in a specific clinical environment. In this setting, both faculty and students have a chance to observe, directly and together, the effectiveness of specific treatments.

• The extent to which the treatment in question is a “standard of practice” in the medical community or is moving toward that standing. Students entering a profession become part of a professional community, and part of their learning involves knowing what the standards and typical practices of that community are. There is often a gap in time between the publication of scientific evidence of the effectiveness of a new treatment and the widespread adoption of that treatment by most or all members of a professional community, along with some appropriate caution and skepticism about new findings that seem to run counter to daily experience. Teachers train students in what the members of the professional community typically do on a daily basis as well as what the published literature says that they could or should do.

Clinicians treating patients have a somewhat more complex set of information requirements about treatment effectiveness, because they must know not only what has worked or what should have been effective in the abstract but also what they are actually able to do in the context of their own training and skills, their own practice settings, and their own sets of patients. Their requirements for information on treatment effectiveness include

• All of the preceding criteria, although many active clinicians will not have the same amount of time as their researcher or faculty colleagues do to monitor developments in the published literature.

• Consistency of a new practice with other aspects of current practice. A psychotherapist may accept the published evidence about the effectiveness of a specific herb for the treatment of depression but may be unwilling to incorporate the use of the herb into his or her own practice because of a professional commitment to therapies based on a different theory and conceptual model of mental illness.

• The availability of essential equipment, trained staff, supplies, and anything else necessary to provide a treatment safely and effectively. Many treatments require specialized equipment, training, or support staff that are not readily available to all clinicians.

• Difficulty in learning new skills (e.g., for new surgical procedures).

• The acceptability of a new treatment to patients and others in the community. Health care is usually a two-way human interaction; and po-