Knowing that factionalism had harmed the progress of Project Sign, Ruppelt did his best to avoid the kinds of open-ended speculation that had led to Sign's personnel being split among advocates and critics of the extraterrestrial hypothesis. As Michael Hall writes, "Ruppelt not only took the job seriously but expected his staff to do so as well. If anyone under him either became too skeptical or too convinced of one particular theory, they soon found themselves off the project." In his book, Ruppelt reported that he fired three personnel very early in the project because they were either "too pro" or "too con" one hypothesis or another. Ruppelt sought the advice of many scientists and experts, and issued regular press releases (along with classified monthly reports for military intelligence).