Analyze each of the following scientific reports, explaining how the pattern of the method of agreement is manifested by each. Discuss, in each case, the limitations of the method of agreement as applied to that quest for a causal connection.

The relation between male circumcision and HIV infection has been a concern of the British medical journal, The Lancet, for many years. Before the turn of this century investigators studying that relation wrote, in The Lancet, that studies going back as far as 1989 showed a very greatly increased risk of HIV-1 infection for men who are not circumcised. The epidemiological and biological evidence that links the two, they later wrote, “has become compelling.” Very recent studies in Kenya and Uganda have produced evidence that is even more compelling. In 2006, trials in those countries conducted by the U.S. National Institutes of Health were stopped because the results were so clear! It appeared that circumcision reduces a man’s risk of contracting AIDS from heterosexual sex by about half, and therefore U.S. officials concluded that it would have been unethical to continue without offering circumcision to all 8,000 men in the trials. The final figures, reevaluated and published in The Lancet on 23 February 2007, are even more striking. They suggest that circumcision reduces a man’s risk of contracting AIDS by as much as 65 percent. Dr. Anthony Fauci, of the National Institute of Allergy and Infectious Diseases, was emphatic: “Look. This is a one-time, permanent intervention that’s safe when done under appropriate medical conditions. If we had an AIDS vaccine that was performing as well as this, it would be the talk of the town.”