Harvard professor Herbert Benson performed a "Study of the Therapeutic Effects of Intercessory Prayer (STEP)" in 2006. The STEP, commonly called the "Templeton Foundation prayer study" or "Great Prayer Experiment", used 1,802 coronary artery bypass surgery patients at six hospitals. Using double-blind protocols, patients were randomized into three groups, individual prayer receptiveness was not measured. The members of the experimental and control Groups 1 and 2 were informed they might or might not receive prayers, and only Group 1 received prayers. Group 3, which served as a test for possible psychosomatic effects, was informed they would receive prayers and subsequently did. Unlike some other studies, STEP attempted to standardize the prayer method. Only first names and last initial for patients were provided and no photographs were supplied. The congregations of three Christian churches who prayed for the patients "were allowed to pray in their own manner, but they were instructed to include the following phrase in their prayers: "for a successful surgery with a quick, healthy recovery and no complications". Some participants complained that this mechanical way they were told to pray as part of the experiment was unusual for them. Complications of surgery occurred in 52 percent of those who received prayer (Group 1), 51 percent of those who did not receive it (Group 2), and 59 percent of patients who knew they would receive prayers (Group 3). There were no statistically significant differences in major complications or thirty-day mortality.