THE REAGAN CAMPAIGN has tried speaking in parables recently. Its parable is contained in the TV commercial that shows a bear rambling across the landscape in a threatening manner while a narrator says: "There is a bear in the woods. For some people the bear is easy to see. Others don't see it at all. Some people say the bear is tame. Others say it is vicious and dangerous. Since no one can really be sure who's right, isn't it smart to be as strong as the bear -- if there is a bear?" Then there appears a man with a rifle, which gives the bear pause. And last the written message: "President Reagan. Prepared for Peace."

According to a story in The Post, the Reagan people tested the ad on "focus groups" of watchers and found that 6 out of 10 people remembered it -- the highest rating for any of their ads -- and that of these six, half got the idea: the bear was Russia and the man with the rifle was the president. The only trouble was that they also found that many of those who didn't get it were way, way off, seeing it as, say, an environmental message.

That's one of the dangers of speaking in parables, which were probably intended for a higher use than political campaigns. To prove the point, we collected additional data by polling our own focus groups, with the following results:

3 out of 10 thought it was an ad for a body- building course, but were skeptical about its promise to make them "as strong as the bear" and wondered what it had to do with President Reagan.

3 out of 10 believed the armed man to be Clint Eastwood.

2 out of 10, both members of the National Rifle Association, saw it as an entering wedge for gun control because the man had only one weapon.

4 out of 10 not only perceived the basic elements of the parable but also saw these additional details: the trees were looming deficits, the clouds the danger of high tariffs, the underbrush the Persian Gulf and the sunlight the dawning of a new day for ad men whose most creative impulses in the field of political advertising had until now been stifled.

1 out of 10 said we had at this point reached a total of 13 out of 10 and were not to be taken seriously as a viable alternative.