Spring is abloom . . . and you're still searching for a Significant Other? The answer, says psychologist Jeffrey Young, is reducible to five critical factors:

Opportunity--the number of eligible members of the opposite sex to whom you're exposed each month; Selectivity--the percentage of those you meet whom you find attractive/desirable; Approach--the percentage of that group with whom you actually initiate contact/ask for a date; Desirability--the percentage of those who agree to go out with you; Intimacy--the percentage of dates that lead to an intimate relationship of at least six months duration.

Young, who works in the University of Pennsylvania psychiatry department, came up with his formula when he realized that many singles cannot find "a satisfactory intimate relationship." He interviewed "lovers and seekers" to find what "factors give people problems in developing intimate relationships."

When he presented these five factors as a mathematical formulation, people could see "effects," says Young, 33 and single. They could "double the number of opportunities or be half as selective." By isolating the problem, they could take active steps to deal with it. "It was in their control."

To figure your own "intimacy equation" using the five factors above: 0.7 M= O x S x A x D x I

In Young's formula, M stands for number of months it will take to form an intimate relationship. The probability factor of 0.7 is based on the 70 percent chance that the equation's answer will come true.

Express O as number of new people you meet in one month; express S, A, D, and I as percentages of 100 (e.g., under Selectivity, if you find two persons in 10 who meet your standards, write it as .2).

The average number of months it takes to find an intimate relationship? About nine months, says Young. High Notes--You are a classical music lover with a 500-album collection in your apartment, season tickets to the National Symphony and the opera, yet cannot find someone of the opposite sex with whom to share your musical passions. An esthetic antidote to this dilemma: membership in the Classical Music Lovers' Exchange, Box 31, Pelham, N.Y. 10803.

"My husband was a music lover and we attended concerts together," says founder and special-education teacher Tamara Monique Conroy, of Pelham. "When I was widowed, I discovered it was very difficult to find men who had the same interests as myself. Music means so much to me. I couldn't live without music. I need it like air to breathe."

Over 6,000 requests for information since its founding 2 1/2 years ago have resulted in an on-going membership of about 2,200.

The group attracts professionals from all fields, including performing musicians, with an age range of 20 to over 70 and a median age of 45.

All members fill out a complete biographical profile and a two-line description form. The fee of $22 for six months entitles members to a complete listing of number-coded, two-line descriptions of other participants and a new list and newsletter each month. Copies of complete profiles of members of the opposite sex ($1 per profile) may be requested.

A measure of its success: music lovers drop out because they have struck a chord--including at least six marriages--with others sharing their interests. Man Sharing: Dilemma or Choice (And for Whom)--May 24, 6-9 p.m. Howard Inn, 2225 Georgia Ave. NW, the Langston Room.

This workshop for women deals with the issue of exclusivity in relationships with men. "It comes up as an issue all the time," says family therapist/trainer Audrey B. Chapman. "Whether married, in a committed relationship or dating, they don't have to experience themselves as victims. They can control how they respond to the situation."

Is it a women-only problem? No, but "women are," says Chapman, "more vocal about how it feels and what it does to them than men."

Sponsored by the Howard University Counseling Service. Fee: $10; free to Howard University Students, with ID. 636-6870 for information.