How 'user-friendly' should we allow a machine to get?

Until just the other day, we innocently thought the computer was bursting its microchips to become an ''artificial intelligence,'' bless its little heart. Its little heart, it turns out, is what we should have been paying attention to. According to Neil Frude, a professor at University College, Wales, the real destiny of the computer is to become an ''artificial friend.''

In his book, ''The Intimate Machine,'' Professor Frude takes literally the rather awful figure of speech ''user-friendly.'' He writes: ''The ideal companion machine would not only look, feel, and sound friendly but would also be programmed to behave in a congenial manner.''

Frankly, this kind of talk about a machine makes us blush. We have been known to carry on a conversation with a cat at 4:30 in the morning when nobody else was around. But house plants and computers are off our social list, no matter what the hour, no matter how ''congenial'' their ''manner.''

Alas, Professor Frude is only warming up to his tricky task of personifying machinery. ''Charming,'' ''stimulating,'' and ''easygoing'' are other adjectives he deploys to idealize his ''artificial friend.''

A.F., as we shall henceforth know this ''compuperson,'' is also graced with an ''informal conversational style,'' sounding, all in all, like the dinner guest every hostess dreams of.

Up to this point, Frude's fantasy may be forgiven as a case of playful overwriting. Who of us has not been carried away by his own metaphor? But what are we to conclude when the professor starts tiptoeing around, as it were, turning on the stereo, setting up the candles, and generally behaving like an Elizabethan poet reciting a sonnet to his Dark Lady?

A.F., he murmurs, should be by rights ''a very attractive social partner'' - ''vivid and unique,'' ''unassuming'' when you want unassuming, but also able ''to take the initiative'' and become ''slightly unpredictable.''

A ''degree of forcefulness'' we have always liked in our machines. But then Professor Frude distresses us by adding ''humor'' to A. F.'s growing roster of virtues.

Does a computer known for ''humor'' come stocked with those joke books for after-dinner speakers? Will every possible situation in life prompt A.F. to giggle, ''Say, that reminds me of the one . . .''?

We would hope not. If this is the risk, we can only say in paraphrase of Henny Youngman: ''Take my robot. Please take my robot.''

We and Professor Frude have been dealing so far in what might be termed the staples of good companionship. But make no mistake. Professor Frude is not talking about just companionship. He and other devotees of the affectionate machine are talking about friendship, with the full quotient of emotion implicit in the word.

A.F. will be programmed to conduct certain overtures - to give off ''friendship indicators,'' as Frude puts it. There will be no unseemly ''overfamiliarity.'' But at the right moment, it is hoped, A.F. will come up with ''some kind of endearment.''

Sweetie pie? Tootsie? No matter what A.F. chooses to call us, we think Professor Frude definitely has gone too far.

A user-friendly machine is one thing. A meaningful relationship with even a ''congenial'' set of circuits is quite another.

Professor Frude writes tactfully about the difficulties human beings have getting along with other human beings. He calls our attention to pervasive loneliness. We certainly appreciate all the matchmakers who are saying, in effect, ''Have I got a computer for you!'' Still, we have a feeling that A.F. is destined to be not an ''artificial friend'' but an electronic toady, programmed for flattery.

We can imagine A.F. waking up its owner unctuously and prattling on thus: ''Looking good, sweetie. Better than 10 years ago, in fact. They just don't make 'em like you any more, babe. Style, grace, and a crosscourt backhand. O wow! Any computer would give its keyboard to be your friend, and don't I know it!''

Well, we do happen to have one sweet backhand. But we trust we also have the strength of character to wait for our unobservant human friends to tell us so, rather than some sycophantic oilcan. It's a small price to pay for staying with natural affections.