The voters of Cambridge overwhelmingly rejected the 17 controversial School Committee appointments and the proposed abolition of proportional representation at the polls yesterday. It was a clear sweep for the Cambridge Civic Association on the two referendum questions in this year's election.

Mayor Edward J. Sullivan and the four majority members of the School Committee received an unmistakable rap on the knuckles from the voters for having attempted to appoint 17 teachers and coaches, without apparent qualifications, over objections from School Committeeman Judson T. Shaplin '42, associate dean of the Graduate School of Education.

The city disapproved of the appointments by a significant 21,000 to 10,000 margin. There was no majority in any of Cambridge's 11 wards favoring the School Committee's action.

On the question of PR, which was placed on the ballot and publicized by the Sullivan forces largely to draw attention from the first referendum, the vote was 18,000 to 13,000 in favor of retaining this system of balloting.

But the results of the elections, which under PR will take about a week to compute, will undoubtedly dampen the presently growing enthusiasm of CCA members. They have won on the campaign issues, but voters are unlikely to change the usual pattern and to give the CCA a majority either on the Council or on the School Committee.

Incumbents are almost always reelected, under the PR system. Thus, though Sullivan has lost a moral victory, he and the Councilors will probably retain their Council seats past Dec. 31.

At present, while the ballots are being kept padlocked at the Longfellow School, those interested in the city affairs can only make wild guesses as to who has won.