The Committee on Undergraduate Education (CUE) yesterday approved a plan to toughen sophomore standing requirements by increasing the minimum score students must attain on three Advanced Placement (A.P.) exams from 3 to 4.

The CUE chose the plan, proposed by the Educational Resources Group (ERG), over a stiffer option recommended by Mack I. Davis, director of advanced standing, which would grant sophomore standing only to students who received a score of 4 on four A.P. exams. The highest possible grade is 5.

Under the present rules, students must take three A.P. exams and earn a minimum score of 3 on each.

Despite the 9-0 CUE vote--with one abstention--in favor of the ERG plan, Davis said he will still propose and support his plan before the Faculty Council next week, because he believes students should take four A.P. exams to replace the four full-year Harvard courses they will miss by accepting sophomore standing.

Davis said he expects some Council support for this reason.

Glen W. Bowersock '57, associate dean of the Faculty on undergraduate education, and chairman of CUE, said yesterday he will represent the ERG plan before the council. Davis did not present a persuasive case, Bowersock said, adding Davis might have evidence that four AP exams qualified students more for sophomore standing than three exams, but "I didn't see it."

Because of the decisive vote, Bowersock suggested Davis consider backing the CUE-approved plan instead.

But Davis said he intends to support requiring four A.P.s because he believes students who take that number "provide more breadth."

Steve Gold '80, co-chairman of ERG, said yesterday ERG considered four A.P.s "an excessive burden."

Although Davis said he has no conclusive proof that four A.P. exams better prepared students for sophomore standing, he noted in the past four years a higher percentage of the students who took four A.P.s with a grade of 4 accepted sophomore standing than those who took three A.P. exams with a grade of 3.

But Davis added these results do not necessarily imply that students with four A.P. exams are more qualified for sophomore standing.

Requiring eligible sophomore standing students to take four A.P. exams will not place an unreasonable burden on them in high school. Davis said, adding "a lot of our students do four 4's quite easily."

Richard J. Herrnstein, professor of Psychology and a member of CUE disagreed, adding taking four A.P. exams might "lock your entire high school program into concrete."

Taking one more A.P. exam does not clearly prepare a student any more for sophomore standing, Herrnstein said. "We are not trying to discover whether someone is virtuous but whether he is a sophomore" he added