Inside look at the difficult art of screenwriting

A unique exploration of the creative process of screenwriting arrives on television this coming Sunday: Screenwriters: Word Into Image (PBS, Sundays, 10- 11 p.m., for six successive weeks. premiering Oct. 10 - check local listings; not all stations may have scheduled this program).

The show journeys into the complex thinking of six prominent American screenwriters in an attempt to determine the basis for the satisfactions as well as dissatisfactions of the individual artists, the accomplishments and the failures of their films. The premiere focuses on William Goldman, who scripted ''Butch Cassidy and the Sundance Kid'' and ''All the President's Men.'' Other screenwriters to be featured in future programs include Neil Simon, Paul Mazursky, Eleanor Perry, Carl Foreman, and Robert Towne.

Mr. Goldman insists that dialogue doesn't really matter, although it is preferable to have good dialogue rather than bad. It is structure which is all-important, he insists. The screenwriter must decide on the main theme of his film and then write scenes which push that theme forward. Wonderful scenes not related to the ''spine'' of the film only throw the film off balance.

Mr. Goldman stresses the adversary relationship between the writer and the director, making it clear that he feels the director has been given too much credit. He berates ''the lunatic myth'' that film is a director's medium rather than a writer's medium.

Produced and directed by award-winning filmmakers Terry Sanders and Freida Lee Mock, ''Screenwriters'' is basically a series of exciting conversations with creative people who usually restrict their words to paper. It can serve as a stimulating lesson for potential screenwriters as well as an entertaining insight into the movies we are offered in our local theaters.