Engineering is a varied discipline with many subfields, including biomedical engineering, chemical engineering, civil and environmental engineering, electrical and computer engineering, geological engineering, industrial and systems engineering, mechanical engineering and materials science. While doctoral programs in each of these emphases have specific requirements for their students, some requirements span the subfields.
Most universities in the U.S. require applicants to hold a Bachelor of Science degree from an accredited university in a field related to the area of engineering they want to pursue. However, some doctoral programs require applicants to hold or be earning a Master of Science degree before applying. Students' quantitative scores on the Graduate Record Examination also determine their admission: "U.S. News & World Report" calculated that in 2011, students who were admitted to the top 100 engineering schools had an average score of 161 out of 170 points.
Preliminary and Qualifying Exams
All doctoral programs in engineering require students to take a qualifying examination, and some require a preliminary examination as well. If a preliminary exam is part of the program, it usually takes place soon after students enter the program, within the first term or first year. This exam tests general knowledge of the field. The qualifying exam is administered by the doctoral committee after students complete their coursework, and it tests whether students are prepared to design and conduct the research necessary to complete their dissertation.
The amount of coursework that engineering students must take varies, depending on their specialty and whether their university is on the quarter or semester system, but it usually takes one to two years to complete. Many programs require students to maintain a minimum GPA during this phase. During the coursework phase, students select their adviser and their doctoral committee. After advancing to candidacy, doctoral programs usually require students to register for a term or two of thesis credits, and after that they are considered "all but dissertation," or ABD.
Usually as part of the qualifying exam, students submit a dissertation prospectus outlining a research project that makes an original contribution to their field. Once their committee approves the prospectus, students spend the rest of their time in the program, usually one to three years, performing the research and writing the dissertation. Along the way, they frequently publish dissertation chapters as articles in peer-reviewed engineering journals. Once their committee has approved all the chapters, students hold their dissertation defense and subsequently make any revisions that their committee requires before approving the degree conferral.