This week, in part seven of our Foreign Student Series, we talk more about accreditation of American colleges and universities. To become accredited, programs have to meet quality standards that are set by an accrediting agency. In the United States, private organizations around the country handle this process. Schools must be reaccredited every ten years, or sooner. They can lose their accreditation if they have problems that are not corrected within a given period of time. For example, the George Washington University Medical School announced last week that it was correcting problems found by its accrediting agency. The medical school in Washington, D.C., has been given two years to meet the standards. School officials said the changes include writing more detailed course objectives and providing more study areas for students. The process of accreditation is designed in part to protect against "diploma mills." These operations call themselves colleges or universities but provide no real education. In August, a husband and wife were sentenced to three years in federal prison in a case in the northwestern state of Washington. They operated Saint Regis University and more than one hundred other diploma mills. These businesses supplied worthless degrees to more than nine thousand people in the United States and around the world. The couple got seven million dollars. George Gollin, a physics professor at the University of Illinois, is an expert on accreditation who helped investigate the case. He advises students to get the exact name of a school they are interested in, then look for it on the Web site of a group known as CHEA. CHEA is the Council for Higher Education Accreditation. The address is chea.org. Make sure a school or program is accredited by a legally recognized accrediting agency before paying any money. Only legitimate schools and programs are listed on the site. It also lists the only legally recognized agencies. Experts advise students to be suspicious of offers from schools that do not require much work or interaction with teachers. One warning sign is any offer of college credit for "life experience."