Although there are no formal standards for power (sometimes referred to as ), most researchers assess the power of their tests using  = 0.80 as a standard for adequacy. This convention implies a four-to-one trade off between -risk and -risk. ( is the probability of a type II error, and α is the probability of a type I error; 0.2 and 0.05 are conventional values for and ). However, there will be times when this 4-to-1 weighting is inappropriate. In medicine, for example, tests are often designed in such a way that no false negatives (type II errors) will be produced. But this inevitably raises the risk of obtaining a false positive (a type I error). The rationale is that it is better to tell a healthy patient "we may have found something—let's test further," than to tell a diseased patient "all is well."