Citing the difficulty in introducing series, CBS senior VP of planning and research David Poltrack said his network will now use summer premieres as a means of testing shows, which could then be extended into the fall or simply re-ordered for midseason.

Poltrack, addressing the National Academy of Television Arts & Sciences at a New York luncheon, said CBS had “a new approach” to back-up programming that involved ordering a limited number of episodes for summer instead of waiting until January to see if new shows have potential. “In other words,” he said, “we will try out our back-up series in advance of the season, not in the middle of the season.”

CBS already has announced summer premieres for the new series “Tall Hopes, “”The Building,””Big Wave Dave’s,””Ned Blessing” and “The Boys.” The web used a similar approach last season, premiering “Raven” last summer, then continuing the series into the fall. A few shows, such as “Tom” and “704 Hauser Street,” still will be held for midseason.

With 38 new series this fall on the three networks and Fox Broadcasting Co. — compared to an average of 21 a year during the early 1980s — new programs “really have the odds stacked against them,” Poltrack said. The four services are each offering more than six new hours, even though no network has successfully launched more than five hoursof new programming in a single season and the average in recent years has been 2 1/2 hours.

Poltrack added that action-adventure shows were down to just 13% of the three webs’ prime time material, due both to low ratings and the goal of reducing violent content in prime time.

The CBS exec also used the forum to chide the press for criticizing the coming season as being “safe,” maintaining that critics overlook quality shows such as “Murder, She Wrote” while waxing poetic about the likes of Steven Bochco’s envelope-pushing drama “NYPD Blue.”

The CBS exec closed with a final barb at the press, saying he didn’t know what would succeed next fall but that “the winners will continue to place the opinions and preferences of the viewers ahead of those of the critics.”