Qual FAQ

What is the purpose of the Qual?

The primary purpose of the Qual is to determine whether or not a student may successfully pursue PhD research in physics at Illinois. It achieves this goal by testing the student's ability to answer eight problems in mainstream, basic physics: two problems in each of quantum mechanics (QM), statistical physics (SP), electromagnetism (EM) and classical mechanics, including relativistic kinematics (CM).

A secondary purpose of the Qual is to ensure that all Illinois PhDs have attained a suitable level of competence in a broad range of basic topics. Specifically, while the material tested is encountered in undergraduate courses, the level of facility expected is that of graduate level.

Does the Qual filter for research ability?

The Qual does not attempt to identify those who will be excellent at research. Rather it attempts to identify those whose demonstrated ability with basic physics is sufficiently poor that it does not seem appropriate to proceed to or continue with research. We feel that an early diagnosis helps students to find a more fruitful enterprise at an early enough stage that they still have strong potential to succeed with their chosen career paths.

How should I prepare for the Qual?

The best preparation for the Qual is to attempt previous years' exams. These are available on-line qual archive. A sensible way to prepare is to attempt an old Qual under exam conditions, so that one's areas of ignorance or lack of facility are clearly exposed. Reviewing this material and then iterating this process a number of times will quickly identify and improve areas of weakness.

Some students form study groups and work problems together. We encourage this activity, but strongly suggest that it does not replace individual study, as described above.

We estimate that a month's preparation time is sufficient and will be of considerable benefit to the consolidation of your physics knowledge and facility.

If I need a refresher, what courses will help me prepare for the Qual?

The Qual is primarily a test of undergraduate material, so the following undergraduate courses are appropriate and valuable to take if you believe that your previous training was weak in any area:

Mechanics - Physics 326

E & M - Physics 436 (formerly 336)

Statistical physics - Physics 427 (formerly 361)

Quantum mechanics - Physics 486 (fall)/Physics 487 (spring) or Physics 580 (formerly 386/387 and 480)

Isn't the Illinois Qual really hard?

The Illinois Qual is a test of undergraduate material, at the depth and level appropriate for Ph.D students. It is not a set of trick questions; it is designed to test fundamental understanding of basic principles. Comparing pass scores, the manner in which the Qual is administered, and the problems themselves reveals that the Illinois Qual is relatively standard, and certainly tests simpler material than that at some of our peer institutions. Students may make this comparison themselves by checking the on-line qual archive.

Isn't Illinois the only physics department with a Qual?

No. Most physics departments that we surveyed have some sort of qualifying examination, serving the same purpose as ours. Some departments put more stress on oral exams than we do. Others test more advanced subjects.

Isn't the Illinois Qual harder to pass than comparable exams at peer institutions?

No. The average pass rate on the Illinois Qual is about 66 percent. However, each student has two attempts to take it, plus a free shot. Of all incoming students, less than 10 percent are terminated from the deparment because of the Qual performance. These figures are about average across departments that we surveyed.

Is the Qual graded on a curve?

No. When the Qual is written, the authors assess what score on each problem would represent a satisfactory performance and qualify for a pass score. Each candidate's score is compared with a priori measure of performance. The overall prior estimate of a pass grade is obtained by summing these priori passing scores. Finally, the pass line is determined generously by seeking a gap in the spectrum of scores close to the prior estimate of the pass score.

Should I take the free shot when I start graduate school at Illinois?

The purpose of the free shot is to enable a student to take the Qual without any possibility of adverse consequences; thus, failure on the free shot will still permit a student to take the exam a further two times and will not affect any teaching or research appointment. However, passing the free shot is a bona fide pass.

The free shot should not be regarded as a gamble or opportunity to be used carelessly. We recommend that each freeshot candidate undertake the same level of preparation as other candidates. Taking any exam, including the Qual, without adequate preparation can be a discouraging experience.