I am 16 years old. I believe I have some insight on the contraception/clinic issue for two obvious reasons: first, I am a member of a group, high school students, directly affected by the question, and second, I am very familiar with the opinions of other teen-agers and the reasons for their actions. I predict general agreement among teen-agers with the following four points.

1.No teen-ager will abstain from sex because a clinic offering birth control is prevented from being placed in the community. Thus, if the idea for lowering the teen-age pregnancy rate is to avoid making contraceptives available, it won't work.

2.Likewise, no teen-ager will become sexually active because condoms are suddenly available at a local clinic (or even at school). On the contrary, many are likely to engage in sex without contraception to avoid the inconvenience, difficulty or embarrassment of obtaining contraceptives.

3.No teen-ager will refrain from sex, or not obtain what is felt to be a needed abortion, if federal funding for abortions, or for information about abortion as an option, is cut off. The proposition that teen-agers simply won't become pregnant if we hide abortions as an option is ludicrous.

4.The institution of sex-ed courses in public schools, particularly necessary in light of AIDS, will not promote promiscuity. This flies in the face of Thomas Strunck's argument {letters, Nov. 26} that a mandatory ''family life course'' is responsible for large numbers of pregnancies in Northern Virginia.

Teen-agers are sexually active for a number of reasons, few of which, if any, relate to the existence of clinics or sex-ed classes, the availability of condoms or federal funding for abortions. Therefore, free counseling in the case of pregnancy, clinics and candor about sexuality will not add to unwanted pregnancies or encourage sexual activity. Period.

This is not to say that morals are not an essential element to the question, as Mr. Strunck suggests, or that instilling a positive mind-set into those most likely to become teen-age mothers, as William Raspberry maintains {op-ed, Nov. 23}, is not a valid and effective remedy to the problem. However, the question of when and with whom to have sex is one of morals and values -- which should be addressed at home and has no place in the public discussion.

Teaching morals may well be the most effective method of preventing teen-age pregnancies. And if that's the case, then it is the responsibility of parents with teen-agers to instill what they deem to be appropriate values, not of the public to determine acceptable sexual practices and then to preach them. Any sort of preaching will inevitably lead to rebellion, whereas an educational, realistic approach will promote awareness and encourage good judgment. It may or may not be good morals to engage in premarital sex, but it is, indisputably, good judgment to wear a condom when doing so.

What is needed is a twofold educational process: one part is the responsibility of the family, the other of the government.

NINA PLANCK Purcellville, Va.