This week's announced $712 rise in tuition, room and board will hit parents hardest, but it may have far-ranging effects within the University itself.

The increase came as no surprise, but its size--9.6 per cent, up to $8140--shocked many students.

University officials blame inflation, chiefly food and fuel costs, for the size of the rise.

Last year's inflation was the worst since 1974, Thomas O'Brien, vice president for financial affairs, said this week. In addition, the Faculty of Arts and Sciences policy of trying to break even on all room and board charges passes inflation costs directly on to students and their parents.

However, the financial aid office should have enough money next year to continue providing aid for all students who show they need it, O'Brien said.

The University may have some extra help from the federal government in meeting aid costs. President Carter's proposed budget for 1980 calls for increased funding for Federal Basic Educational Opportunity Grants and the federal work-study program, Martha C. Lyman, director of financial aid, said this week.

While aid officers are adding up columns of figures to see whether they can pay for the increase, student leaders have begun raising their voices. The Student Assembly shows "wanton disregard for students' ability to pay."

But assembly leaders said there are no plans yet for organized protest--they're leaving the issue for their successors after next week's elections.

Robert J. Ginn Jr., director of the Office of Career Services and Off-Campus Learning, said yesterday he doubts the tuition tise will discourage students from taking leaves of absence for fear of future tuition increases. "The reasons that people take leaves usually transcend financial considerations," he said.

Admissions officers said they expect the rise will not affect college admissions since Harvard's chief competitors have announced similar increases. Yale's tuition will be identical to Harvard's next year, Stanford's only slightly lower.

But officials fear that the boost may discourage potential applicants such as middle income students who are ignorant of Harvard's financial aid possibilities.

"You tell me what the inflation will be like next year, and I could tell you about tuition," O'Brien said.