Getting into college is one thing; staying long enough to graduate is another.

There are certain courses college students must clear to earn a bachelor's or associate's degree.

If you don't pass anatomy and physiology at Westmoreland County Community College, you will not be able to complete any program in allied health. More than a quarter of students fail or withdraw from the first anatomy and physiology course.

If you can't pass organic and inorganic chemistry at Shippensburg University of Pennsylvania, you won't be able to complete a biology major. Biology chair Gregory Paulson considers it one of the biggest reasons students leave his major. Of students of all disciplines enrolling in the entry-level chemistry course, 42 percent fail or withdraw.

If your entering skills are so low that you have to take the lowest level of remedial math at Community College of Allegheny County, there is a 6 in 7 chance you won't pass a college-level math course, a necessity for many programs.

Students hit these kinds of hurdles both in courses that are gatekeepers to advancing in their majors and those that are electives needed to fill core course requirements.

These hurdles are particularly important because the number of courses a student withdraws from or repeats -- in attempts to pass a course or raise a passing grade -- can dramatically decrease the student's chance of graduating.

In a U.S. Department of Education study of college transcripts, researcher Clifford Adelman called excessive withdrawals without penalty and repeated courses "one of the most degree-crippling features" on the transcripts.

He even put a number on it: If a student withdraws from or repeats 20 percent or more of the courses attempted, the chance of completing a degree is cut in half.

Many schools don't publicly provide or haven't looked at figures about which courses have the highest rates of failures and withdrawals.

When the Post-Gazette asked more than 30 colleges and universities for such data, few had readily available numbers, some produced them with effort, and others declined, some saying it would be too difficult to determine or were private.

The Policy Center on the First Year of College learned the answers can be surprising when it asked a variety of schools participating in its Foundations of Excellence program to share failure rates of D's, F's, W's and incompletes for their five courses with the highest freshmen enrollments.

Most were "floored" by their rates, said Randy Swing, formerly co-director of the policy center and now executive director of the Association for Institutional Research.

He said one four-year school had a rate of 72 percent with D's, F's, W's or incompletes in one of its biggest courses.

"That's beyond belief," he said. "We regularly saw them in the upper 30 percent range [at four-year campuses], and at two-year campuses, 40 percent and 50 percent were not rare at all."

Dr. Swing said low success rates in some math and science classes weren't a surprise, but the high rates of low marks in introductory psychology courses were.

"We just kept seeing them show up in the top five high enrollments. We kept seeing them with 30 or higher percent."

In courses with high rates of low grades, Dr. Swing said, "It doesn't always mean it's hard teachers or bad teachers. It could have been the course was ill-suited for freshmen.

"The bottom line is that a large group of people not doing well in a course should be addressed. It's not something students can fix."

Some other large courses that tended to make the policy center's list included introductory courses in English and biology as well as remedial math and remedial English at less-selective schools.

The association didn't publicly release the data, although Dr. Swing advocates schools letting students know such results to help them in course selection and placement.

He said the information wouldn't deter students but instead would be a way to show them a path to success and encourage them to follow it.

"In the absence of that information, I think many students are making bad decisions simply because they don't know they're bad decisions," he said.

Some schools offer information or options that may reduce failure and withdrawal rates.

Lock Haven University of Pennsylvania advises math-challenged students against taking physics and offers some chemistry courses -- chemistry in the environment and forensic chemistry -- for those not majoring or minoring in natural sciences.

Only 16 percent of the students in its first standard chemistry course -- Principles of Chemistry 1 -- failed or withdrew in 2006, and only 9 percent did so in Physics 1.

Westmoreland County Community College saw its rate of failure and withdrawal in anatomy and physiology fall from 42 percent in fall 2006 to 27 percent in fall 2007.

One of the instructors, assistant professor Susanne Kalup, said the college made a concerted effort to see that students already had a chemistry background and offered extra instruction outside of the regular class. Instructors also coordinated.

In the Post-Gazette survey of more than 30 schools, 16 public campuses provided information about the 10 courses with the most failure and withdrawal rates as well as the rates for certain math courses, freshman composition and the introductory courses to chemistry, biology and physics.

Only one private school, Washington & Jefferson College, provided information, in this case on performance in calculus and certain introductory courses.

The survey results, by school, can be found at post-gazette.com.

All of the public universities count at least one math-oriented class among those in which at least 20 percent of students fail or withdraw. In a small number of cases, the failures and withdrawals topped 50 percent.

Colleges commonly require at least one math course -- or a course that counts as quantitative reasoning such as logic or computer science -- to graduate. In addition, some majors require additional math-oriented courses, such as statistics, economics and accounting.

Some campuses make a point to offer extra help for courses they know are difficult for students.

While the University of Pittsburgh didn't release numbers for its Oakland campus, it noted that three calculus courses -- Calculus 1, 2 and business calculus -- are the top three courses for which students seek help at the Math Assistance Center.

It also listed the courses for which students most often seek help from the Academic Resource Center: basic applied statistics, General Chemistry 1 and 2, Organic Chemistry 1 and 2, Foundations of Biology 1, Introduction to Physics 1, Introduction to Microeconomic Theory and Introduction to Macroeconomic Theory.

At three local community colleges, the lists of courses often failed also varied, but all counted at least one math class having more than a quarter of the students failing or withdrawing.

Community colleges, which are not selective in their admissions, find many students start out in "developmental" courses that are below college level in math, reading or both.

Some students struggle at that level. At CCAC, more than 40 percent fail or withdraw from both developmental math courses, arithmetic fundamentals and algebra fundamentals.

Kevin Smay, CCAC executive director of strategic planning, said the college found that the longer students stay away from math, the more their skills decline. He recommends taking required math sooner rather than later.

Some schools that track where students are struggling use it to help them succeed.

Community colleges in Allegheny, Beaver and Westmoreland counties are among those participating in Achieving the Dream, which calls for analyzing data and using it to increase achievement.

"We've got to fix this," said Randy Finfrock, director of institutional research and data services at Westmoreland County Community College.

First Published: September 4, 2008, 8:00 a.m.