The other day I heard myself say the most incredible thing to my 5-year-old and his friends.

"Don't ride your Big Wheels in the street, okay?" Initially I didn't think this bit of motherly admonition was that remarkable. I retreated to the quiet of my kitchen. Only then, when I heard the instant replay, did I shudder.

"Okay? "

Can it be true that I had just asked a 5-year-old's permission to please not kill himself in the street? I ran back outside, gathered the children, knelt down so that I could look each in the eye, and said, "Do not ride your Big Wheels into the street."

Better. Much better. My assertiveness-training instructor would have given me an "A" on that one.

My Montgomery County College course actually covers a lot of ground: time management, goal setting, sex role stereotyping, decision making, as well as assertiveness training, a subject I thought I had little use for. After all, I assert myself all over the place, don't I? I mean, I'm not exactly shy about giving forth with my opinions, and last week I really chewed that guy out for doing a lousy job on my car, and I do have a couple of kids to boss around.

Right ?

Wrong. I thought being assertive meant not being a pipsqueak, not being afraid to sound off, yelling louder than the next guy, perhaps even being the squeaky wheel.

What I learned is that assertiveness is not to be confused with aggression.

As described by instructor Sandra Roberts, assertiveness training is based on the idea that each person has basic human rights, and that each will be happier if exercizing -- appropriately -- those rights:

Right to refuse requests without feeling guilty or selfish, right to feel and express anger, right to make mistakes, right to be independent, right to express preferences about others' behavior.

To become more assertive, as instructors stress, you have to practice. Practice giving "I" messages which state your own feelings. Practice recognizing other people's feelings. You don't have to approve or agree, just recognize them. Practice stating what it is you want.

What assertive statements must not do is degrade another; be "paragraphs" long; be "you" statements (You'll be sorry . . .); begin with "I think" or "I feel." And never end with "okay?"

When I tacked an "okay?" to my instructions, what I meant was "Do you understand me?"

What the children heard was, "I don't really mean it; do as you like."

I realized that assertiveness training had to be good for parenting. I decided to start practicing.

My first opportunity was presented almost immediately. Ian, age 8: "Mommy, can Charles stay for supper?"

"No, not tonight."

Ian: "Why?"

Charles: "Why not?"

Both: "Awwwwwwwwwww."

I noticed with great pride that I had not fallen into the paragraph trap. I had resisted the temptation to embellish my "no" with "I don't know when Daddy will be home for dinner, I have only enough pork chops for the four of us, I'm going out at 7:30, Charles doesn't like pork chops anyway, and I don't feel like company tonight because your father wishes to discuss your multiplication tables with you."

I didn't skip a beat when Michael, age 5, in mid-tantrum, shrieked: "I'm not going to do my chore. I don't like it. It's too hard!" Out of my lips miraculously emerged not a "you" message, like "You'll be sorry, and it can't possibly be too hard for you. You did it yesterday, didn't you?"

Not a word of that from assertive mother. Establishing eye contact, I said, "I can see that you are upset by having to do this chore. I guess you think it's pretty hard."

Defused, and challenged. Michael protested, "No, it's not. I'm going to go and do it now."

It may seem obvious, but it's a constant amazement to me how off the track we can get in handling daily situations, particularly when dealing with children.

Parents have rights, too. You have a right to your own feelings and the right to express those feelings to your children; you have the right to be the authority in your home; you have the right to have your marriage come first and your relationship with the children come second, and you have the right to take periodic vacations from being a parent. (Right now I'm working on a plan for the last one.)

Assertiveness training has helped to remind me of these rights and has improved my relationship with my children. But I have to keep reminding myself to practice, and sometimes I backslide a little.

Last week at the supermarket I was heard to remark: "If you two don't knock it off, I'm going to bash your little heads together and tie you to the lobster tank, hands in!"

Oh well . . .another good lesson for children to learn early on is that parents aren't perfect.