In "An Encyclopedia of Claims, Frauds, and Hoaxes of the Occult and Supernatural", Randi wrote, "Hal Puthoff and Russell Targ, who studied Mr. Geller at the Stanford Research Institute, were aware, in one instance at least, that they were being shown a magician's trick by Geller ... Their protocols for this 'serious' investigation of the powers claimed by Geller were described by Ray Hyman, who investigated the project on behalf of the Department of Defense's Advanced Research Projects Agency, as 'sloppy and inadequate.'" Critics have pointed out that both Puthoff and Targ were already believers in paranormal powers and Geller was not adequately searched before the experiments. The psychologist C. E. M. Hansel and sceptic Paul Kurtz have noted that the experiments were poorly designed and open to trickery.