Stuck on some homework? Pick up the phone; ask an expert.

Remember the old one about the teacher sending home a note that asked father to stop helping with the homework -- so Johnny would have a chance to improve? The Educators Association of Porterville, Calif., has a better idea: to help its students, it has activated a homework hot line.

Now, for all those from the first grade through high school in this San Joaquin Valley community, there is research and explanatory help for homework by telephone, four days a week from 6 to 9 p.m.

Two volunteer teachers staff the hot-line phones in donated space at the city library. They cover homework assignments and have on hand special reference material as well as current textbooks from all the grades, 1 to 12.

In addition, there are also after-hours phone numbers of teachers who can help on specialized questions, if referrals are found necessary.

The 300-member central California association developed the hot-line idea after investigations showed a pronounced decline in both the quality and quantity of local school homework.

"Many of our students, we decided, needed auxiliary help. Too many kept telling us things like, 'We didn't understand it' or 'We couldn't find the material' or 'We forgot what you told us about how to do it," an association member said.

Joining the Educators Association's new plan is the Association of Mexican-American Educators. This group has offered to provide Spanish-speaking volunteer teachers either for language instruction or for Spanish-speaking students needing help in regular course work.

The only costs for the new hot line are telephone charges, which are borned by the Educators Association. Through the cooperation of the local school district and the city library, the offi ce space is donated, and the teacher time is all volunteer.