9.2 Multiple Coins from a Single Mint 217 This shrinkage of the estimates of the individual biases is not a problem with the analysis; in fact, the shrinkage accurately reflects our beliefs: If we believe that all the coins have biases generated by the same mint and that the biases depend on the mint, then the flips from the different coins should mutually inform each other's estimated biases. The hierarchical Bayesian analysis is espe- cially nice because it tells us not only the estimates of the biases ( j ) and the mint parameter (µ), but also the degree of dependence () of the biases on the mint parameter. 9.2.4 Case Study: Therapeutic Touch Rosa, Sarner, & Barrett (1998) investigated therapeutic touch (TT) among medical practitioners. TT is a technique in which nurses sweep their hands 5 to 10 cm over a patient's body and (claim to) sense depleted or con- gested areas of the patient's "energy field." The TT practitioners then sweep their hands to "repattern" and smooth the energy field, resulting in healing of the patient. TT has had a notable range of proponents, including some professional organizations (see Rosa, Sarner, & Barrett, 1998, for review).