显微镜下看留学美国

　　At the doctoral level, the Ph.D. (doctor of philosophy) is the most common degree awarded in academic disciplines. Other doctoral degrees are awarded primarily in professional fields, such as education (Ed.D. or doctor of education) and business administration (D.B.A. or doctor of business administration). Doctoral programs involve advanced coursework, seminars, and the writing of a dissertation that describes the student's own original research, completed under the supervision of a faculty adviser.
　　
　　A comprehensive examination is given, usually after three to five years of study and completion of all coursework, and when the student and adviser agree that the student is ready. This exam is designed to test the student's ability to use knowledge gained through courses and independent study in a creative and original way. Students must demonstrate a comprehensive understanding of their chosen field of study. Successful completion of this examination marks the end of the student's coursework and the beginning of concentration on research.
　　
　　The Ph.D. degree is awarded to those students who complete an original piece of significant research, write a dissertation describing that research, and successfully defend their work before a panel of faculty members who specialize in the discipline. This may take an additional two to three years. To earn a doctoral degree, therefore, may take anywhere from five to eight years beyond the bachelor's degree, depend on the field of study.
　　
　　In the United States, you will find a variety of nontraditional doctoral programs; these programs might have very different types of requirements from the traditional programs. Prospective students should be sure of what is required to enter any program they are considering, and what is required to obtain the degree. This information is usually available from university catalogs and websites or directly from individual departments.
　　
　　Course Load and Grading Systems
　　需修课程量及学分系统
　　
　　"Course load" refers to the number of courses students take each term. The normal course load for a graduate student is three or four courses, which equals approximately nine to 12 credits per term. The U.S. Immigration and Naturalization Service requires that international students take a course load that is considered full-time by the institution.
　　
　　Passing grades are typically awarded on a scale of "A" through "D," and "F" indicates a failing grade for a course. An average grade of "B" is usually the minimum required for completion of a graduate degree program. Other grading systems may include a grade-point scale from 0 to 3, 4, or 5; pass/fail; high pass/low pass; or other variations.
　　
　　Credit, course load, grading systems, and requirements vary between institutions. Make sure you are aware of the policies of an individual program and institution before you apply.
　　
　　
　　Non-Degree Study at a U.S. University
　　美国大学的无学位进修
　　
　　Do you want to study in the United States at a college or university, but not for a full degree? Perhaps you want to experience life on a U.S. campus, while improving your knowledge of certain subjects. This is certainly a useful addition to your educational experience, and U.S. colleges welcome students such as you. You should write to universities, explain your situation, and request information on applying for "special student" or "non-degree student" status. See Short-Term Study for more information on opportunities in the United States.