The letters went out to hundreds of prominent people around the state of Illinois. They said simply: "Hope you have a nice day. I'm Ben Alexander, the new president of Chicago State University."

"People sat up and noticed this," recalls Alexander, whose appointment as the second president of the University of the District of Columbia becomes effective today. "They said, 'This guy's different.' That's what turned people on. The governor called me up. He wanted to know who is this man."

Benjamin Harold Alexander believes it often pays to be different. And different he is. His unorthodox way of introducing himself here eight years ago was just the opening shot in his battle to improve the image of a little-esteemed state university.

As he leaves Chicago State, Alexander elicits strong feelings, both positive and negative. But friends and foes alike agree he accomplished what he set out to do.

The trim, bespectacled former research chemist, now 60, also had a mandate to improve academic standards at the commuter school on Chicago's south side. By most measures, the academic programs at Chicago State have indeed improved, although few of the ideas for change came directly from Alexander himself.

When Alexander took over in 1974, the school was in danger of losing its accreditation. For example, about 66 percent of the university's education majors were failing the National Teachers Exam.

Over the next eight years, he worked at stiffening the school's grading system, expanding course offerings and strengthening overall graduation requirements. The school now has a five-year accreditation.

And, he says, the proportion of education majors who pass the teachers' test has doubled to 70 percent--still only average, but an improvement over the past. And although his relations with teachers were somewhat stormy here, Alexander is credited with generally improving CSU.

"There are still a lot of students there who don't belong there, and it's an unfortunate situation," said Dominick J. Bufalino, chairman of the Illinois Board of Governors of State Colleges and Universities, which oversees Chicago State. "But now I would have to give the institution a passing grade . . . Four or five years ago it was strictly a diploma mill."

Alexander brought a distinctive and unexpected style to CSU. He strode about the school's grassy, tree-lined campus wearing a white lab coat, a holdover from his days at the National Institutes of Health. He played racquetball with Illinois Gov. Jim Thompson, appeared in national magazines as a member of the educational in-crowd, and turned up at endless functions, tirelessly promoting the school he fondly called "beautiful Chicago State University."

In some respects, Alexander's sharp public relations sense and Madison Avenue acumen for what attracts attention is just what the UDC board of trustees was seeking at a time when the university is trying to improve its image.

UDC is also grappling with the issue of academic standards, trying to reconcile the ideal of sound standards with the reality of open admissions and the fact that many of its students come out of the D.C. public schools needing remedial help.

"You just have to talk with the guy 20 minutes to know he's controversial," Ronald H. Brown, the UDC board member who headed the search for a new president, said recently in Washington.

Brown says a majority of the UDC trustees believes Alexander's ability will outweigh his often quixotic personality and his gift for attracting controversy like a lightning rod.

UDC and Chicago State, both urban commuter schools, are at once very similar and very different institutions. Chicago State has 7,441 students, nearly 99 percent of them Chicago-area residents, and an annual budget of $27.1 million. UDC is about twice as large, with 14,115 students--91 percent of them D.C. residents--and a budget of $63 million.

About 77 percent of Chicago State students and 85 percent of UDC students are black. The average age of the CSU undergraduates is 27; at UDC it is 26.

UDC has open admissions, while Chicago State accepts only about 66 percent of freshman applicants, according to Alexander. About 60 percent of the school's students need remedial help in reading, English or mathematics. About 70 percent of UDC freshmen must enroll in remedial English and 82 percent are enrolled in either basic math or remedial algebra.

Chicago State's faculty and administration is predominantly white. UDC's faculty and administration is overwhelmingly black.

Alexander was the first black president of Chicago State. When he took over he had little experience in the field of education, except for one term on the D.C. school board, from 1966-68, and his work as a part-time professor at American University and the U.S. Department of Agriculture graduate school. Instead of bringing specific proposals, he came with a broad idea of improving academic standards and demanding excellence from the students and his staff.

Jeffrey R. Ladd, the attorney who was then president of Chicago State's governing board, recalled how Alexander, the son of a steel mill worker, impressed board members as "a man who had pulled himself up by his bootstraps."

Asked why he wanted the position, Alexander told the board, "I've never failed at a job in my life."

In the next eight years, Alexander made numerous changes in programs and policy. Acting on recommendations from his staff and the faculty, he expanded remedial programs for students who came to the university with poor reading and math skills.

Today, all Chicago State students must pass basic reading, mathematics and English composition proficiency exams before graduation. UDC has similar requirements in English and math.

Alexander also eliminated a controversial no-fail grading system. Under this system, students who did little or no work received an "R" grade instead of an "F" and were asked to repeat the course. Some 40 percent of the students were getting R grades when he arrived, Alexander said.

Some students, community leaders and educators said Alexander's move to eliminate no-fail punished slower students. Alexander argued that such a grading system merely "dooms people to the junk heap of no success."

Alexander also expelled 130 students and placed 1,000 others on academic probation, saying a review of the records indicated that they were just "hanging around" on campus and not bound for graduation.

His administration established premedicine and predentistry programs and schools of nursing, business and administration and allied health, offering majors in such fields as dietetics and medical records administration and occupational therapy.

Today, 72 percent of the nursing graduates who take the state exam for nursing certification pass, compared to the 21 percent that passed in 1977. Of the 19 graduates last year who applied to professional schools in the health field, nine were accepted to medical school, four to dentistry schools and five to schools of pharmacy.

Faculty members and current and former CSU administrators give Alexander credit for these accomplishments, though some say the steps would probably have been taken no matter who was president because the university's accreditation was on the line.

"The president sets the leadership tone of the institution . . . But I am not so naive as to believe the university wouldn't have improved if he hadn't come here," said Chicago State's current academic vice president, William W. Sutton. Any president, Sutton said, would have made the changes Alexander did, "if he or she was worth anything."

According to a report issued in 1976 by the North Central Association of Colleges and Schools just before it accredited the school, CSU failed to receive the full 10-year accreditation because evaluators believed faculty morale and input into planning needed improvement.

They also wanted to see more minority representation within the administration and faculty. To some extent, these problems were longstanding and predated Alexander's tenure. The school's accreditation is up for renewal this year.

"What Alexander has done is given the students at the school reason to hope. He took kids . . . and said, let's love them and make them feel good about themselves," said Donald E. Walters, executive director of the CSU board of governors.

Alexander had an open-door policy for students, but strained relations with the university's faculty.

In the beginning, said Marion Taylor, the former head of the faculty senate, Alexander tried to keep a stronghold over the university budget, and made a point of giving money back to the state at the end of the fiscal year. "I would not let them spend money unless it could be spent wisely and economically," Alexander said.

Faculty members also complained that he was capricious in granting tenure. As Alexander leaves, there are 12 lawsuits pending against the university involving tenure decisions, discrimination claims and salary disputes during his term.

Women faculty members complain his record of hiring and promoting women was poor and that he did little to correct inequities in their salaries. The women also complain that there are only two women deans at Chicago State, one in the college of nursing, the other in the college of education. Both, however, were appointed by Alexander. There are nine deans altogether.

Alexander says that "in every case, I followed university and board of governors guidelines in granting tenure and promotions." He said he agreed to pay out about $250,000 in compensation to some 60 women professors "against the advice of my peers" in the case of one class-action suit. But the professors, he said, argued they deserved much more.

"He did not know you were supposed to work with the faculty in any kind of collegial sense," said Allan De Giulio, who was academic vice president of Chicago State from 1975 to 1978.

"He would continually overturn faculty recommendations while at the same time expressing how 'beautiful' the faculty was," said De Giulio, now provost of Fairleigh Dickinson University in New Jersey.

Alexander's relations with the black community here have also been mixed. In some quarters, he is viewed with esteem. A Chicago church, for example, invited him to speak as a stand-in for the renowned black educator Benjamin Mays. But others have criticized him for his stands against black studies, busing to achieve racial balance and the recognition of black English.

Timuel Black, an English professor at the Kennedy-King Community College here and a well-known local community activist, said Alexander did little to attract middle-class black students and more quality black professors to CSU, 63 percent of whose current faculty is white.

Criticism from blacks, Alexander says, affects him deeply. He recalls his days as a civil rights activist in the late 1940s when he and others integrated a restaurant in Peoria, Ill. The day blacks were finally admitted, he says, the waitress who served him spit in his plate.

Alexander, an energetic man whose body never seems at rest--he is always bouncing up and down in his chair, jiggling one foot as he stands speaking to a visitor--was born in Roberta, Ga.

His father moved the family to Cincinnati when Alexander was 2. His mother, whom he calls the most influential force in his life, was a deeply religious woman who told him education is "the way to go from the valley to the mountaintop."

Following her advice to "never go into an easy field," he earned three degrees in chemistry: a bachelor's from the University of Cincinnati, a master's from Bradley University in Peoria, and a PhD from Georgetown University.

His last job before coming to Chicago State was as a grants manager with the National Institutes of Health, dispensing financial aid to help disadvantaged students enter fields in science. "I felt I was more needed in education than in a high-level soft job in the federal government," he says of his decision to seek Chicago State's presidency.

The criticism he has received from blacks here, he maintains, stems from the fact that he tried to make Chicago State a multiracial university and did not randomly replace white employes with blacks.

"Blacks have got to get out of the trick bag of asking for more than their fair share because people aren't going to give it to them," he says.

In Washington, Alexander will be paid $59,500 and live in a presidential residence that was newly purchased by the university. He replaces Lisle C. Carter Jr., who served as the first president of the university, which was formed through the merger five years ago of Federal City College, Washington Technical Institute and D.C. Teachers College.

Already, some UDC faculty members and trustees have criticized his selection. Alexander's response: "I'll love the hell out of them."