Presidential candidate Edward M. Kennedy (D-Mass.) gave half a dozen campaign speches around the Northeast last week, but in many ways the most instructive of the lot was a speech that was never spoken.

Kennedy's speech, or, more precisely, nonspeech, was a fairly routine swat at President Carter's economic policies, and to most people it would probably not seem a very big deal.

But to "experienced political observers" which campaign reporters call themselves, it was something to shout about. And the shouting offers an insight into the curious species of reality that sometimes shows up as political news.

Media outlets nationwide reported today that Kennedy,

Media outlets nationwide reported today that Kennedy, campaigning here, delivered his sharpest attack yet on Carter. The real attacker, though, was a ghost writer on Kennedy's staff. The senator scrubbed the "attack" at the last minute -- but by then it was already a reported "fact."

The Washington Post did not report this nonspeech. Candor, though, requires the admission that his was as much a function of luck as of perspicacity.

The incident occured, or, more precisely, didn't occur, at a Democratic fund-raiser here Friday night, the last stop of Kennedy's first week of full-scale presidential campaigning.

For political reporters, who like nothing better than the sight of candidates swatting openly at one another, Kennedy's week was a disappointment. He took many pokes at Carter, but he did it indirectly.

Mostly, Kennedy used the "those who say" gambit.

He would open with the phrase "there ae those who say . . . ," and then enunciate some position Carter has taken. Having set forth what "those who" had said, Kennedy would proceed to rip into their positions.

For the reporter, this poses a dilemma. Sure, Kennedy probably meant Carter, but if he did, why didn't he just say "Carter"?

This frustration seemed to be at an end, though, when Kennedy's plane arrived here Friday. The campaign staff handed out a prepared text of the speech Kennedy was supposed to give later that night, and in the new text Kennedy was blasting, not merely "those who," but "the president" and "the administration."

"The president speaks of a decade of high inflation . . . but there are peaks and valleys in that decade. And the highest peak . . . has erupted since the present administration came to power."

This looked like hot news, and on arriving at the fund-raiser two dozen reporters clattered downstairs to call in the breakthrough. When they clattered back up, though, they discovered that Kennedy had not uttered a word of the prepared speech, substituting instead a routine demand that fuel prices be lowered in the Northeast.

Before anybody could get back to the telephones, though, the Secret Service herded the whole entourage off to the airplane.

Reporters are a skittish group in general, and this development brought their latent paranoia babbling to the surface.

Those who had filed the story felt sick about reporting something that hadn't happened. "I can see the presses running now," moaned a reporter from a New York paper. "They'll print 750,000 papers before I can get to a phone."

But those who hadn't filed felt no better. After all, the text had been distributed by Kennedy's staff, which gave it a patina of officialness. And if all the other guys were reporting it . . .

The only person on the plane who wasn't upset was Kennedy, who found the whole thing hilarious.

"You guys'll find other jobs somehwere," he laughed, sucking on a long cigar. "Anyway I stand by all that stuff in the text -- peaks, valleys, whatever that stuff was. I'll say it sooner or later."

The most curious event of all came two hours later, when the plane set down and reporters finally called their editors. Some editors apparently felt the story was so good that it wash't worth dropping, even though Kennedy had not said what the text had him saying.

To mollify the press corps somewhat, the candidate threw a few crumbs at their feet at the end of the long night.

He had been asked hundreds of times what date he would formally declare his candidacy and now, he said, he would answer.

"Well, it'll probably be some day before Thanksgiving," he said, and turned away in a haze of smoke.