Naturalistic science fiction
In Theory...
Naturalistic Science Fiction (NSF) is a realistic take on the SF genre, avoiding typical SF cliches, utilizing visual and artistic elements from such dramas as The Sorpranos and The West Wing.
In Practice...
For BSG this means that characters are viewed as normal, every-day people. There will be no characters that are simply the "smoking chauvinist", "loyal soldier", "heroic lead", "spiritual commander", "whiz-kid genius", or "sexy doctor".
Technology is far enough advanced for star travel to be possible (see: FTL travel) and plausable; no Star Trek matter-energy conversion tech, phaser weapons or other unrealistic SF deus ex machina exist.
There are no "planet-of-the-week" episodes. A majority of BSG's episodes primarily focus on internal fleet survival issues (see: Water or Bastille Day). There will be an absense of aliens, a la Joss Whedon's Wikipedia:Firefly (Series)Firefly]], for planets will be mostly uninhabitable and lifeless (with sound, scientific reasoning).
BSG avoids the thematic eloments found in Star Wars and episodic storytelling, using a documentary feel for the series and tribal music.